One document matched: draft-schulzrinne-sipping-sos-04.ps

%!PS-Adobe-2.0
%%Creator: dvips(k) 5.86d Copyright 1999 Radical Eye Software
%%Title: sos.dvi
%%Pages: 10
%%PageOrder: Ascend
%%BoundingBox: 0 0 612 792
%%DocumentFonts: Times-Roman Times-Bold Helvetica CMSY10 Courier
%%+ Times-Italic
%%EndComments
%DVIPSWebPage: (www.radicaleye.com)
%DVIPSCommandLine: dvips -o
%+ /home/hgs/html/sip/drafts/draft-schulzrinne-sipping-sos-04.ps sos
%DVIPSParameters: dpi=600, compressed
%DVIPSSource:  TeX output 2003.01.08:0952
%%BeginProcSet: texc.pro
%!
/TeXDict 300 dict def TeXDict begin/N{def}def/B{bind def}N/S{exch}N/X{S
N}B/A{dup}B/TR{translate}N/isls false N/vsize 11 72 mul N/hsize 8.5 72
mul N/landplus90{false}def/@rigin{isls{[0 landplus90{1 -1}{-1 1}ifelse 0
0 0]concat}if 72 Resolution div 72 VResolution div neg scale isls{
landplus90{VResolution 72 div vsize mul 0 exch}{Resolution -72 div hsize
mul 0}ifelse TR}if Resolution VResolution vsize -72 div 1 add mul TR[
matrix currentmatrix{A A round sub abs 0.00001 lt{round}if}forall round
exch round exch]setmatrix}N/@landscape{/isls true N}B/@manualfeed{
statusdict/manualfeed true put}B/@copies{/#copies X}B/FMat[1 0 0 -1 0 0]
N/FBB[0 0 0 0]N/nn 0 N/IEn 0 N/ctr 0 N/df-tail{/nn 8 dict N nn begin
/FontType 3 N/FontMatrix fntrx N/FontBBox FBB N string/base X array
/BitMaps X/BuildChar{CharBuilder}N/Encoding IEn N end A{/foo setfont}2
array copy cvx N load 0 nn put/ctr 0 N[}B/sf 0 N/df{/sf 1 N/fntrx FMat N
df-tail}B/dfs{div/sf X/fntrx[sf 0 0 sf neg 0 0]N df-tail}B/E{pop nn A
definefont setfont}B/Cw{Cd A length 5 sub get}B/Ch{Cd A length 4 sub get
}B/Cx{128 Cd A length 3 sub get sub}B/Cy{Cd A length 2 sub get 127 sub}
B/Cdx{Cd A length 1 sub get}B/Ci{Cd A type/stringtype ne{ctr get/ctr ctr
1 add N}if}B/id 0 N/rw 0 N/rc 0 N/gp 0 N/cp 0 N/G 0 N/CharBuilder{save 3
1 roll S A/base get 2 index get S/BitMaps get S get/Cd X pop/ctr 0 N Cdx
0 Cx Cy Ch sub Cx Cw add Cy setcachedevice Cw Ch true[1 0 0 -1 -.1 Cx
sub Cy .1 sub]/id Ci N/rw Cw 7 add 8 idiv string N/rc 0 N/gp 0 N/cp 0 N{
rc 0 ne{rc 1 sub/rc X rw}{G}ifelse}imagemask restore}B/G{{id gp get/gp
gp 1 add N A 18 mod S 18 idiv pl S get exec}loop}B/adv{cp add/cp X}B
/chg{rw cp id gp 4 index getinterval putinterval A gp add/gp X adv}B/nd{
/cp 0 N rw exit}B/lsh{rw cp 2 copy get A 0 eq{pop 1}{A 255 eq{pop 254}{
A A add 255 and S 1 and or}ifelse}ifelse put 1 adv}B/rsh{rw cp 2 copy
get A 0 eq{pop 128}{A 255 eq{pop 127}{A 2 idiv S 128 and or}ifelse}
ifelse put 1 adv}B/clr{rw cp 2 index string putinterval adv}B/set{rw cp
fillstr 0 4 index getinterval putinterval adv}B/fillstr 18 string 0 1 17
{2 copy 255 put pop}for N/pl[{adv 1 chg}{adv 1 chg nd}{1 add chg}{1 add
chg nd}{adv lsh}{adv lsh nd}{adv rsh}{adv rsh nd}{1 add adv}{/rc X nd}{
1 add set}{1 add clr}{adv 2 chg}{adv 2 chg nd}{pop nd}]A{bind pop}
forall N/D{/cc X A type/stringtype ne{]}if nn/base get cc ctr put nn
/BitMaps get S ctr S sf 1 ne{A A length 1 sub A 2 index S get sf div put
}if put/ctr ctr 1 add N}B/I{cc 1 add D}B/bop{userdict/bop-hook known{
bop-hook}if/SI save N @rigin 0 0 moveto/V matrix currentmatrix A 1 get A
mul exch 0 get A mul add .99 lt{/QV}{/RV}ifelse load def pop pop}N/eop{
SI restore userdict/eop-hook known{eop-hook}if showpage}N/@start{
userdict/start-hook known{start-hook}if pop/VResolution X/Resolution X
1000 div/DVImag X/IEn 256 array N 2 string 0 1 255{IEn S A 360 add 36 4
index cvrs cvn put}for pop 65781.76 div/vsize X 65781.76 div/hsize X}N
/p{show}N/RMat[1 0 0 -1 0 0]N/BDot 260 string N/Rx 0 N/Ry 0 N/V{}B/RV/v{
/Ry X/Rx X V}B statusdict begin/product where{pop false[(Display)(NeXT)
(LaserWriter 16/600)]{A length product length le{A length product exch 0
exch getinterval eq{pop true exit}if}{pop}ifelse}forall}{false}ifelse
end{{gsave TR -.1 .1 TR 1 1 scale Rx Ry false RMat{BDot}imagemask
grestore}}{{gsave TR -.1 .1 TR Rx Ry scale 1 1 false RMat{BDot}
imagemask grestore}}ifelse B/QV{gsave newpath transform round exch round
exch itransform moveto Rx 0 rlineto 0 Ry neg rlineto Rx neg 0 rlineto
fill grestore}B/a{moveto}B/delta 0 N/tail{A/delta X 0 rmoveto}B/M{S p
delta add tail}B/b{S p tail}B/c{-4 M}B/d{-3 M}B/e{-2 M}B/f{-1 M}B/g{0 M}
B/h{1 M}B/i{2 M}B/j{3 M}B/k{4 M}B/w{0 rmoveto}B/l{p -4 w}B/m{p -3 w}B/n{
p -2 w}B/o{p -1 w}B/q{p 1 w}B/r{p 2 w}B/s{p 3 w}B/t{p 4 w}B/x{0 S
rmoveto}B/y{3 2 roll p a}B/bos{/SS save N}B/eos{SS restore}B end

%%EndProcSet
%%BeginProcSet: 8r.enc
% @@psencodingfile@{
%   author = "S. Rahtz, P. MacKay, Alan Jeffrey, B. Horn, K. Berry",
%   version = "0.6",
%   date = "1 July 1998",
%   filename = "8r.enc",
%   email = "tex-fonts@@tug.org",
%   docstring = "Encoding for TrueType or Type 1 fonts
%                to be used with TeX."
% @}
% 
% Idea is to have all the characters normally included in Type 1 fonts
% available for typesetting. This is effectively the characters in Adobe
% Standard Encoding + ISO Latin 1 + extra characters from Lucida.
% 
% Character code assignments were made as follows:
% 
% (1) the Windows ANSI characters are almost all in their Windows ANSI
% positions, because some Windows users cannot easily reencode the
% fonts, and it makes no difference on other systems. The only Windows
% ANSI characters not available are those that make no sense for
% typesetting -- rubout (127 decimal), nobreakspace (160), softhyphen
% (173). quotesingle and grave are moved just because it's such an
% irritation not having them in TeX positions.
% 
% (2) Remaining characters are assigned arbitrarily to the lower part
% of the range, avoiding 0, 10 and 13 in case we meet dumb software.
% 
% (3) Y&Y Lucida Bright includes some extra text characters; in the
% hopes that other PostScript fonts, perhaps created for public
% consumption, will include them, they are included starting at 0x12.
% 
% (4) Remaining positions left undefined are for use in (hopefully)
% upward-compatible revisions, if someday more characters are generally
% available.
% 
% (5) hyphen appears twice for compatibility with both 
% ASCII and Windows.
% 
/TeXBase1Encoding [
% 0x00 (encoded characters from Adobe Standard not in Windows 3.1)
  /.notdef /dotaccent /fi /fl
  /fraction /hungarumlaut /Lslash /lslash
  /ogonek /ring /.notdef
  /breve /minus /.notdef 
% These are the only two remaining unencoded characters, so may as
% well include them.
  /Zcaron /zcaron 
% 0x10
 /caron /dotlessi 
% (unusual TeX characters available in, e.g., Lucida Bright)
 /dotlessj /ff /ffi /ffl 
 /.notdef /.notdef /.notdef /.notdef
 /.notdef /.notdef /.notdef /.notdef
 % very contentious; it's so painful not having quoteleft and quoteright
 % at 96 and 145 that we move the things normally found there to here.
 /grave /quotesingle 
% 0x20 (ASCII begins)
 /space /exclam /quotedbl /numbersign
 /dollar /percent /ampersand /quoteright
 /parenleft /parenright /asterisk /plus /comma /hyphen /period /slash
% 0x30
 /zero /one /two /three /four /five /six /seven
 /eight /nine /colon /semicolon /less /equal /greater /question
% 0x40
 /at /A /B /C /D /E /F /G /H /I /J /K /L /M /N /O
% 0x50
 /P /Q /R /S /T /U /V /W
 /X /Y /Z /bracketleft /backslash /bracketright /asciicircum /underscore
% 0x60
 /quoteleft /a /b /c /d /e /f /g /h /i /j /k /l /m /n /o
% 0x70
 /p /q /r /s /t /u /v /w
 /x /y /z /braceleft /bar /braceright /asciitilde
 /.notdef % rubout; ASCII ends
% 0x80
 /.notdef /.notdef /quotesinglbase /florin
 /quotedblbase /ellipsis /dagger /daggerdbl
 /circumflex /perthousand /Scaron /guilsinglleft
 /OE /.notdef /.notdef /.notdef
% 0x90
 /.notdef /.notdef /.notdef /quotedblleft
 /quotedblright /bullet /endash /emdash
 /tilde /trademark /scaron /guilsinglright
 /oe /.notdef /.notdef /Ydieresis
% 0xA0
 /.notdef % nobreakspace
 /exclamdown /cent /sterling
 /currency /yen /brokenbar /section
 /dieresis /copyright /ordfeminine /guillemotleft
 /logicalnot
 /hyphen % Y&Y (also at 45); Windows' softhyphen
 /registered
 /macron
% 0xD0
 /degree /plusminus /twosuperior /threesuperior
 /acute /mu /paragraph /periodcentered
 /cedilla /onesuperior /ordmasculine /guillemotright
 /onequarter /onehalf /threequarters /questiondown
% 0xC0
 /Agrave /Aacute /Acircumflex /Atilde /Adieresis /Aring /AE /Ccedilla
 /Egrave /Eacute /Ecircumflex /Edieresis
 /Igrave /Iacute /Icircumflex /Idieresis
% 0xD0
 /Eth /Ntilde /Ograve /Oacute
 /Ocircumflex /Otilde /Odieresis /multiply
 /Oslash /Ugrave /Uacute /Ucircumflex
 /Udieresis /Yacute /Thorn /germandbls
% 0xE0
 /agrave /aacute /acircumflex /atilde
 /adieresis /aring /ae /ccedilla
 /egrave /eacute /ecircumflex /edieresis
 /igrave /iacute /icircumflex /idieresis
% 0xF0
 /eth /ntilde /ograve /oacute
 /ocircumflex /otilde /odieresis /divide
 /oslash /ugrave /uacute /ucircumflex
 /udieresis /yacute /thorn /ydieresis
] def

%%EndProcSet
%%BeginProcSet: texps.pro
%!
TeXDict begin/rf{findfont dup length 1 add dict begin{1 index/FID ne 2
index/UniqueID ne and{def}{pop pop}ifelse}forall[1 index 0 6 -1 roll
exec 0 exch 5 -1 roll VResolution Resolution div mul neg 0 0]/Metrics
exch def dict begin Encoding{exch dup type/integertype ne{pop pop 1 sub
dup 0 le{pop}{[}ifelse}{FontMatrix 0 get div Metrics 0 get div def}
ifelse}forall Metrics/Metrics currentdict end def[2 index currentdict
end definefont 3 -1 roll makefont/setfont cvx]cvx def}def/ObliqueSlant{
dup sin S cos div neg}B/SlantFont{4 index mul add}def/ExtendFont{3 -1
roll mul exch}def/ReEncodeFont{CharStrings rcheck{/Encoding false def
dup[exch{dup CharStrings exch known not{pop/.notdef/Encoding true def}
if}forall Encoding{]exch pop}{cleartomark}ifelse}if/Encoding exch def}
def end

%%EndProcSet
%%BeginFont: CMSY10
%!PS-AdobeFont-1.1: CMSY10 1.0
%%CreationDate: 1991 Aug 15 07:20:57

% Copyright (C) 1997 American Mathematical Society.  All Rights Reserved.

11 dict begin
/FontInfo 7 dict dup begin
/version (1.0) readonly def
/Notice (Copyright (C) 1997 American Mathematical Society. All Rights Reserved) readonly def
/FullName (CMSY10) readonly def
/FamilyName (Computer Modern) readonly def
/Weight (Medium) readonly def
/ItalicAngle -14.035 def
/isFixedPitch false def
end readonly def
/FontName /CMSY10 def
/PaintType 0 def
/FontType 1 def
/FontMatrix [0.001 0 0 0.001 0 0] readonly def
/Encoding 256 array
0 1 255 {1 index exch /.notdef put} for
dup 15 /bullet put
readonly def
/FontBBox{-29 -960 1116 775}readonly def
/UniqueXX 5000820 def
currentdict end
currentfile eexec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0000000000000000000000000000000000000000000000000000000000000000
0000000000000000000000000000000000000000000000000000000000000000
0000000000000000000000000000000000000000000000000000000000000000
0000000000000000000000000000000000000000000000000000000000000000
0000000000000000000000000000000000000000000000000000000000000000
0000000000000000000000000000000000000000000000000000000000000000
0000000000000000000000000000000000000000000000000000000000000000
0000000000000000000000000000000000000000000000000000000000000000
cleartomark

%%EndFont 
TeXDict begin 40258431 52099146 1000 600 600 (sos.dvi)
@start /Fa 139[25 7[25 6[40 3[45 50[23 46[{
TeXBase1Encoding ReEncodeFont}5 90.9091 /Times-Italic
rf /Fb 139[30 35 40 1[51 45 51 76 25 2[25 3[40 51 40
1[45 11[66 1[51 66 8[35 14[30 58[{TeXBase1Encoding ReEncodeFont}18
90.9091 /Times-Bold rf /Fc 134[55 55 1[55 55 55 55 55
1[55 55 55 55 55 55 1[55 55 55 55 55 55 55 1[55 9[55
6[55 3[55 3[55 3[55 55 1[55 55 2[55 1[55 55 55 55 55
55 55 1[55 55 55 55 1[55 55 10[55 34[{TeXBase1Encoding ReEncodeFont}44
90.9091 /Courier rf /Fd 240[45 15[{}1 90.9091 /CMSY10
rf /Fe 166[53 3[53 44 40 49 53 40 53 53 65 44 2[24 53
2[44 53 49 1[53 65[{TeXBase1Encoding ReEncodeFont}17
72.7272 /Times-Roman rf /Ff 134[42 42 60 42 42 23 32
28 42 42 42 42 65 23 2[23 42 42 28 37 42 37 42 37 11[60
51 46 55 1[46 6[28 2[46 5[76 5[23 11[21 28 21 2[28 28
37[46 2[{TeXBase1Encoding ReEncodeFont}38 83.022 /Times-Roman
rf /Fg 139[28 32 37 14[37 46 42 31[60 65[{TeXBase1Encoding ReEncodeFont}
7 83.022 /Times-Bold rf /Fh 133[45 1[45 66 1[51 25 45
30 51 51 51 51 76 20 45 1[20 51 51 25 51 51 45 51 51
7[61 3[66 56 61 66 1[61 71 66 76 3[25 1[71 56 61 1[66
61 61 92 5[25 10[25 25 30 45[{TeXBase1Encoding ReEncodeFont}44
90.9091 /Helvetica rf /Fi 134[50 1[72 50 55 33 39 44
1[55 50 55 83 28 2[28 55 50 33 44 1[44 55 50 11[72 66
55 72 1[61 1[72 94 66 78 1[39 2[61 66 1[72 1[72 10[50
2[50 50 50 50 1[25 33 45[{TeXBase1Encoding ReEncodeFont}41
99.6264 /Times-Bold rf /Fj 134[60 1[86 60 66 40 47 53
66 66 60 66 100 33 66 1[33 66 60 40 53 66 53 66 60 11[86
80 66 86 1[73 1[86 1[80 2[47 93 93 1[80 86 86 80 86 7[60
60 60 60 60 60 60 60 60 60 6[40 40 40 36[66 2[{
TeXBase1Encoding ReEncodeFont}52 119.552 /Times-Bold
rf /Fk 133[33 37 37 54 37 37 21 29 25 37 37 37 37 58
21 37 1[21 37 37 25 33 37 33 37 33 11[54 46 42 2[42 54
1[66 1[54 29 25 54 1[42 46 54 50 1[54 5[21 2[37 1[37
37 3[37 37 1[19 25 19 2[25 25 37[42 2[{TeXBase1Encoding ReEncodeFont}52
74.7198 /Times-Roman rf /Fl 107[40 40 24[40 45 45 66
45 45 25 35 30 45 45 45 45 71 25 45 25 25 45 45 30 40
45 40 45 40 3[30 1[30 56 66 66 86 66 66 56 51 61 1[51
66 66 81 56 66 35 30 66 66 51 56 66 61 61 66 84 40 1[51
1[25 25 45 45 45 45 45 45 45 45 45 45 25 23 30 23 1[45
30 30 30 35[51 51 2[{TeXBase1Encoding ReEncodeFont}80
90.9091 /Times-Roman rf end
%%EndProlog
%%BeginSetup
%%Feature: *Resolution 600dpi
TeXDict begin

%%EndSetup
%%Page: 1 1
1 0 bop 0 87 a Fl(Internet)25 b(Engineering)i(T)-7 b(ask)23
b(F)o(orce)0 200 y(INTERNET)-8 b(-DRAFT)2633 b Fk(H.)18
b(Schulzrinne)0 313 y Fl(draft-schulzrinne-s)q(ipp)q(in)q(g-s)q(os-)q
(04)q(.ps)2180 b Fk(Columbia)20 b(U.)3272 426 y Fl(January)25
b(8,)e(2003)3148 539 y(Expires:)30 b(June)24 b(2003)58
738 y Fj(Emer)o(gency)29 b(Ser)o(vices)h(f)m(or)g(Inter)n(net)g(T)-11
b(elephony)31 b(based)f(on)h(the)f(Session)g(Initiation)1588
888 y(Pr)n(otocol)f(\(SIP\))0 1137 y Fi(Status)d(of)f(this)f(Memo)0
1311 y Fl(This)d(document)i(is)d(an)h(Internet-Draft)k(and)c(is)g(in)g
(full)g(conformance)j(with)d(all)g(pro)o(visions)j(of)d(Section)h(10)f
(of)g(RFC2026.)141 1424 y(Internet-Drafts)28 b(are)d(w)o(orking)h
(documents)h(of)e(the)g(Internet)h(Engineering)h(T)-7
b(ask)25 b(F)o(orce)f(\(IETF\),)f(its)i(areas,)h(and)f(its)0
1537 y(w)o(orking)g(groups.)30 b(Note)24 b(that)g(other)g(groups)h(may)
f(also)g(distrib)n(ute)i(w)o(orking)f(documents)h(as)d
(Internet-Drafts.)141 1650 y(Internet-Drafts)30 b(are)c(draft)h
(documents)i(v)n(alid)e(for)f(a)g(maximum)g(of)h(six)f(months)i(and)e
(may)g(be)h(updated,)h(replaced,)0 1763 y(or)c(obsoleted)j(by)d(other)h
(documents)h(at)e(an)o(y)h(time.)30 b(It)24 b(is)g(inappropriate)k(to)c
(use)g(Internet-Drafts)k(as)c(reference)i(material)0
1876 y(or)d(to)h(cite)g(them)f(other)i(than)f(as)g(\223w)o(ork)g(in)f
(progress.)-6 b(\224)141 1989 y(The)23 b(list)h(of)g(current)h
(Internet-Drafts)i(can)d(be)f(accessed)j(at)d(http://www)-6
b(.ietf.or)n(g/ietf/1id)q(-ab)q(str)q(act)q(s.txt)141
2102 y(T)f(o)23 b(vie)n(w)g(the)h(list)f(Internet-Draft)k(Shado)n(w)c
(Directories,)j(see)e Fh(http://www)-5 b(.ietf)m(.org/shado)o(w)g
(.html)p Fl(.)0 2351 y Fi(Copyright)25 b(Notice)0 2512
y Fl(Cop)o(yright)h(\(c\))d(The)g(Internet)j(Society)e(\(2003\).)30
b(All)23 b(Rights)i(Reserv)o(ed.)1796 2686 y Fg(Abstract)352
2819 y Ff(This)h(document)f(describes)g(ho)n(w)h(Session)h(Initiation)e
(Protocol)g(\(SIP\))h(user)h(agents)e(and)h(proxies)g(can)g(set)h(up)
227 2918 y(emer)o(genc)o(y)e(calls)j(and,)g(more)f(generally)-5
b(,)27 b(reach)g(emer)o(genc)o(y)d(assistance)k(via)f(SIP)h(requests.)
47 b(F)o(or)27 b(that)g(purpose,)227 3018 y(it)d(de\002nes)f(a)g(uni)n
(v)o(ersal)f(emer)o(genc)o(y)e(SIP)k(URI,)f(sip:sos@domain)f(and)h
(sips:sos@domain,)f(that)i(allo)n(ws)f(SIP)g(user)227
3118 y(agents)f(to)h(contact)f(the)h(local)f(emer)o(genc)o(y)e(number)
-5 b(.)30 b(It)23 b(also)g(de\002nes)f(con)m(v)o(entions)e(that)j
(increase)f(the)g(high)g(proba-)227 3217 y(bility)d(of)g(reaching)f
(the)h(appropriate)e(emer)o(genc)o(y)f(call)k(center)-5
b(.)24 b(The)19 b(document)e(does)i(not)g(de\002ne)g(an)o(y)f(SIP)i
(protocol)227 3317 y(e)o(xtensions.)0 3610 y Fj(1)119
b(Intr)n(oduction)0 3817 y Fl(Using)21 b(the)h(PSTN,)c(emer)n(genc)o(y)
23 b(help)e(can)h(often)f(be)g(summoned)i(at)d(a)h(designated,)j
(widely)e(kno)n(wn)f(number)l(,)h(re)o(gardless)0 3930
y(of)28 b(where)h(the)f(telephone)j(w)o(as)d(purchased.)46
b(Ho)n(we)n(v)o(er)l(,)29 b(this)g(number)g(dif)n(fers)h(between)f
(localities,)j(e)n(v)o(en)c(though)i(it)e(is)0 4042 y(often)i(the)f
(same)g(for)g(a)g(country)i(or)e(re)o(gion)h(\(such)g(as)f(man)o(y)g
(countries)i(in)e(the)g(European)i(Union\).)46 b(F)o(or)28
b(end)h(systems)0 4155 y(based)22 b(on)e(the)h(Session)g(Initiation)i
(Protocol)f(\(SIP\))e([1],)h(it)f(is)g(desirable)j(to)d(ha)n(v)o(e)h(a)
f(uni)n(v)o(ersal)j(identi\002er)l(,)f(independent)i(of)0
4268 y(location,)e(to)e(simplify)h(the)f(user)h(e)o(xperience)h(and)e
(to)g(allo)n(w)g(the)g(de)n(vice)h(to)f(perform)g(appropriate)j
(processing.)31 b(Here,)20 b(we)0 4381 y(de\002ne)26
b(a)f(common)h(user)h(identi\002er)l(,)h(\223sos\224,)f(as)e(the)h
(contact)i(mechanism)f(for)f(emer)n(genc)o(y)h(assistance.)38
b(This)26 b(identi\002er)0 4494 y(is)d(meant)h(to)g(be)f(used)i(in)e
(addition)j(to)d(an)o(y)h(local)g(emer)n(genc)o(y)i(numbers.)141
4607 y(W)-7 b(e)28 b(also)h(describe)i(ho)n(w)e(emer)n(genc)o(y)h
(calls)g(are)f(routed)h(to)f(the)g(appropriate)j(emer)n(genc)o(y)f
(call)e(center)h(\(ECC\).)d(\(In)0 4720 y(the)33 b(United)g(States)g
(and)g(Canada,)i(emer)n(genc)o(y)f(call)f(centers)h(are)f(referred)h
(to)f(as)f(Public)h(Safety)g(Answering)h(Points)0 4833
y(\(PSAPs\).\))49 b(Since)31 b(each)h(emer)n(genc)o(y)g(call)g(center)g
(is)e(generally)j(only)f(responsible)i(for)d(a)f(speci\002c)i
(geographic)i(area,)0 4946 y(it)26 b(is)h(important)h(that)f(calls)h
(are)f(routed)h(to)e(the)h(correct)h(ECC.)d(Re)o(gardless)j(of)e
(whether)i(the)f(ECC)e(is)h(connected)j(to)e(the)0 5059
y(PSTN)20 b(or)j(is)f(directly)j(reachable)g(via)e(SIP)-10
b(,)21 b(the)i(netw)o(ork)h(location)h(of)d(the)h(caller)h(has)f
(little)h(relationship)i(to)d(its)f(physical)0 5172 y(location.)30
b(If)19 b(the)h(call)g(is)g(routed)h(through)h(a)d(PSTN)e(gate)n(w)o
(ay)-6 b(,)21 b(the)f(originating)j(number)d(is)g(lik)o(ely)h(either)g
(associated)h(with)0 5284 y(the)h(gate)n(w)o(ay)g(or)g(is)g
(permanently)i(assigned)g(to)e(the)g(IP)f(phone,)i(re)o(gardless)h(of)e
(where)g(it)f(is)h(currently)i(located.)30 b(F)o(or)22
b(SIP-)0 5397 y(based)30 b(ECCs,)d(the)i(IP)e(address)j(or)f
Fh(Contact)d Fl(header)k(information)h(in)d(the)h(call)g(only)g(pro)o
(vides)h(crude)g(approximation)p eop
%%Page: 2 2
2 1 bop 0 100 a Fl(INTERNET)-8 b(-DRAFT)640 b(draft-schulzrinne-)q(sip)
q(pin)q(g-)q(sos)q(-04)q(.ps)629 b(January)25 b(8,)e(2003)0
399 y(as)31 b(to)g(the)h(geographic)i(location)g(of)d(the)g(caller)i
(and)e(may)g(well)g(be)g(completely)j(wrong)e(if)f(virtual)h(pri)n(v)n
(ate)h(netw)o(orks)0 511 y(are)g(used.)56 b(Thus,)35
b(the)d(SIP)g(request)i(needs)f(to)g(con)l(v)o(e)o(y)h(the)f(location)h
(of)f(the)f(caller)i(so)f(that)g(the)f(call)h(can)g(be)g(routed)0
624 y(appropriately)-6 b(.)33 b(Section)24 b(6)f(discusses)j(one)e
(possible)i(approach.)141 737 y(This)j(document)i(does)f(not)g
(introduce)i(an)o(y)d(ne)n(w)f(SIP)g(header)j(\002elds,)f(request)h
(methods,)h(status)e(codes,)i(message)0 850 y(bodies,)25
b(or)f(e)n(v)o(ents.)32 b(User)23 b(agents)j(una)o(w)o(are)f(of)f(the)g
(recommendations)k(in)c(this)g(draft)h(can)g(place)g(emer)n(genc)o(y)h
(calls,)f(b)n(ut)0 963 y(may)d(not)h(be)g(able)g(to)f(pro)o(vide)i(the)
f(same)f(user)h(interf)o(ace)i(functionality)-6 b(.)32
b(The)22 b(document)j(suggests)f(beha)n(vior)h(for)e(proxy)0
1076 y(serv)o(ers,)i(in)e(particular)j(outbound)g(proxy)f(serv)o(ers.)0
1325 y Fi(1.1)99 b(T)-9 b(erminology)0 1499 y Fl(In)18
b(this)h(document,)h(the)f(k)o(e)o(y)f(w)o(ords)h(\223)r
Fe(M)t(U)t(S)t(T)r Fl(\224,)h(\223)r Fe(M)t(U)t(S)t(T)k(N)t(O)q(T)r
Fl(\224,)c(\223)r Fe(R)t(E)t(Q)s(U)t(I)t(R)t(E)t(D)r
Fl(\224,)h(\223)r Fe(S)t(H)t(A)t(L)t(L)r Fl(\224,)h(\223)r
Fe(S)t(H)t(A)t(L)t(L)i(N)t(O)q(T)r Fl(\224,)c(\223)r
Fe(S)t(H)t(O)t(U)t(L)t(D)r Fl(\224,)0 1612 y(\223)r Fe(S)t(H)t(O)t(U)t
(L)t(D)35 b(N)t(O)q(T)r Fl(\224,)c(\223)r Fe(R)t(E)t(C)t(O)t(M)t(M)t(E)
t(N)t(D)t(E)t(D)r Fl(\224,)j(\223)r Fe(M)t(A)l(Y)r Fl(\224,)d(and)e
(\223)r Fe(O)t(P)t(T)t(I)t(O)t(N)r(A)t(L)r Fl(\224)k(are)c(to)h(be)f
(interpreted)k(as)c(described)j(in)d(BCP)0 1725 y(14,)23
b(RFC)f(2119)i([2)q(])f(and)h(indicate)i(requirement)g(le)n(v)o(els)e
(for)g(compliant)h(SIP)d(implementations.)0 2018 y Fj(2)119
b(Requir)n(ements)136 2225 y Fd(\017)46 b Fl(SIP-based)35
b(end)g(systems)g(must)g(be)f(able)h(to)f(reach)h(emer)n(genc)o(y)i
(call)d(centers.)63 b(These)35 b(emer)n(genc)o(y)h(call)f(cen-)227
2338 y(ters)g(may)e(ha)n(v)o(e)i(SIP)d(capabilities)37
b(or)d(may)g(be)g(reachable)i(only)f(via)f(a)f(SIP-to-PSTN)f(gate)n(w)o
(ay)-6 b(.)60 b(Since)34 b(each)227 2451 y(ECC)26 b(serv)o(es)j(only)f
(a)f(limited)i(geographic)h(area,)f(often)g(de\002ned)f(by)g
(jurisdictional)k(boundaries)f(such)d(as)g(state,)227
2564 y(pro)o(vince)e(or)d(county)-6 b(,)25 b(SIP-based)g(emer)n(genc)o
(y)g(requests)h(must)136 2751 y Fd(\017)46 b Fl(While)31
b(current)i(emer)n(genc)o(y)f(call)f(centers)i(are)d(limited)i(to)e(v)n
(oice)i(and)g(TDD)c(\(telecommunication)35 b(de)n(vice)d(for)227
2864 y(the)g(deaf\))g(communications,)37 b(future)32
b(SIP-based)h(ECCs)d(should)j(handle)g(all)e(rele)n(v)n(ant)i(means)f
(of)f(interaction,)227 2977 y(including)26 b(multimedia)f(and)f
(instant)i(messaging)f([8)q(].)136 3165 y Fd(\017)46
b Fl(It)25 b(should)h(be)f(possible)j(for)d(de)n(vices)h(to)f(pro)o
(vide)h(user)g(interf)o(aces)i(that)d(can)g(directly)i(cause)f(an)f
(emer)n(genc)o(y)i(call,)227 3278 y(without)e(the)f(user)g(ha)n(ving)h
(to)f(\223dial\224)g(or)g(type)g(a)f(speci\002c)i(address.)136
3465 y Fd(\017)46 b Fl(Ev)o(en)19 b(as)h(each)g(country)i(is)d(lik)o
(ely)i(to)e(operate)i(their)g(emer)n(genc)o(y)g(calling)g
(infrastructure)j(dif)n(ferently)-6 b(,)23 b(SIP)18 b(de)n(vices)227
3578 y(should)25 b(be)f(able)g(to)g(reach)g(emer)n(genc)o(y)i(help)e
(and,)g(if)f(possible,)i(be)f(located)h(in)f(an)o(y)f(country)-6
b(.)136 3766 y Fd(\017)46 b Fl(While)28 b(tra)n(v)o(eling,)i(users)f
(must)e(be)h(able)g(to)f(use)h(their)h(f)o(amiliar)f(\223home\224)g
(emer)n(genc)o(y)i(identi\002er)-5 b(.)42 b(Users)28
b(should)227 3879 y(also)c(be)g(able)g(to)g(dial)g(the)g(local)g(emer)n
(genc)o(y)i(number)e(in)f(the)h(country)i(the)o(y)e(are)f(visiting.)136
4066 y Fd(\017)46 b Fl(An)o(y)22 b(mechanism)h(must)f(be)g(deplo)o
(yable)j(incrementally)g(and)e(w)o(ork)f(e)n(v)o(en)g(if)g(not)g(all)g
(SIP)f(entities)j(support)g(emer)n(-)227 4179 y(genc)o(y)32
b(calling.)54 b(User)31 b(agents)i(conforming)g(to)e(the)h(SIP)e
(speci\002cation)k([1)q(],)e(b)n(ut)g(una)o(w)o(are)g(of)f(this)h
(document,)227 4292 y(must)24 b(be)f(able)i(to)e(place)i(emer)n(genc)o
(y)g(calls,)f(possibly)i(with)d(restricted)j(functionality)-6
b(.)136 4480 y Fd(\017)46 b Fl(Gi)n(v)o(en)29 b(incremental)j(deplo)o
(yment,)h(emer)n(genc)o(y)f(call)e(functionality)j(should)e(be)f
(testable)h(by)e(the)h(user)g(without)227 4593 y(causing)c(an)d(emer)n
(genc)o(y)j(response.)136 4780 y Fd(\017)46 b Fl(Emer)n(genc)o(y)20
b(calling)f(mechanisms)h(must)e(support)i(e)o(xisting)g(emer)n(genc)o
(y)g(call)f(centers)g(based)h(on)e(circuit-switched)227
4893 y(technology)27 b(as)c(well)h(as)f(future)i(ECC)d(that)i(are)f
(SIP-capable.)136 5081 y Fd(\017)46 b Fl(Emer)n(genc)o(y)27
b(call)e(mechanisms)i(should)g(not)f(require)h(a)e(speci\002c)h
(technology)i(for)e(determining)h(the)f(location)h(of)227
5194 y(the)d(caller)-5 b(.)0 5656 y Fk(H.)18 b(Schulzrinne)1239
b Fl(Expires)25 b(June)f(2003)1240 b([P)o(age)23 b(2])p
eop
%%Page: 3 3
3 2 bop 0 100 a Fl(INTERNET)-8 b(-DRAFT)640 b(draft-schulzrinne-)q(sip)
q(pin)q(g-)q(sos)q(-04)q(.ps)629 b(January)25 b(8,)e(2003)0
399 y Fj(3)119 b(Emer)o(gency)30 b(URIs)0 606 y Fl(A)c(single,)j
(global)g(\(set)f(of\))f(identi\002ers)i(for)f(emer)n(genc)o(y)h
(services)g(is)e(highly)i(desirable,)h(as)e(it)f(allo)n(ws)g(end)h
(system)g(and)0 718 y(netw)o(ork)22 b(de)n(vices)h(to)e(be)h(b)n(uilt)g
(that)g(recognize)h(such)f(services)i(and)d(can)h(act)f(appropriately)
-6 b(.)32 b(Such)21 b(actions)i(may)e(include)0 831 y(restricting)j
(the)e(functionality)j(of)c(the)h(end)g(system,)g(pro)o(viding)i
(special)f(features,)g(o)o(v)o(erriding)h(user)e(service)h(constraints)
0 944 y(or)g(routing)j(session)f(setup)g(messages.)141
1057 y(U)l(As)30 b(that)h(determine)h(that)f(a)f(dialog)i(or)e
(transaction)j(relates)f(to)f(an)f(emer)n(genc)o(y)35
b Fe(M)t(U)t(S)t(T)e Fl(use)e(an)f(emer)n(genc)o(y)j(call)0
1170 y(identi\002er)28 b(in)f(the)h Fh(Request-URI)p
Fl(.)c(The)i Fh(Request-URI)h Fe(M)t(U)t(S)t(T)j Fl(be)d(either)h(an)f
(emer)n(genc)o(y)i(SIP)d(URI)g(de\002ned)i(in)e(Sec-)0
1283 y(tion)e(3.1)g(or)f(an)h(emer)n(genc)o(y)h(tel)f(URI)e(de\002ned)i
(in)g(Section)g(3.2.)0 1528 y Fi(3.1)99 b(SIP)25 b(URIs)f(f)n(or)h
(Emer)o(gency)h(Calls)0 1703 y Fl(It)h(is)j Fe(R)t(E)t(C)t(O)t(M)t(M)t
(E)t(N)t(D)t(E)t(D)i Fl(that)c(SIP-based)g([1)q(])f(end)h(systems)h
(and)f(proxy)h(serv)o(ers)g(support)g(a)e(uniform)i(emer)n(genc)o(y)h
(call)0 1816 y(identi\002er)l(,)25 b(namely)f(the)g(reserv)o(ed)i(user)
e(name)f(\223sos\224)i(within)f(an)o(y)g(domain,)g(e.g.,)109
2049 y Fc(sip:sos@example)o(.c)o(om)109 2162 y(sips:sos@exampl)o(e.)o
(co)o(m)141 2396 y Fl(The)f(reserv)o(ed)i(name)f(is)f(case-insensiti)n
(v)o(e.)141 2509 y(The)i(host)h(part)g(of)g(the)f(emer)n(genc)o(y)j
(URI)e Fe(S)t(H)t(O)t(U)t(L)t(D)i Fl(be)e(the)f(host)h(portion)i(of)d
(the)h(address-of-record)k(of)c(the)f(caller)-5 b(.)0
2622 y(The)23 b(\223sips\224)i(form)g Fe(S)t(H)t(O)t(U)t(L)t(D)i
Fl(be)c(used)i(to)e(ensure)i(inte)o(grity)h(and)d(con\002dentiality)-6
b(.)33 b(All)23 b(SIP)f(requests)j(with)f(URIs)e(of)i(this)0
2735 y(form)f(are)h(assumed)h(to)e(be)h(emer)n(genc)o(y)i(calls.)339
2873 y Fk(The)f(domain-of-record)h(w)o(as)e(chosen)i(since)f(a)f(SIP)f
(user)h(agent)h(may)g(not)g(be)f(able)h(to)f(determine)h(the)g(local)f
(domain)h(it)f(is)227 2964 y(visiting.)33 b(This)21 b(also)i(allo)n(ws)
f(each)g(user)h(to)f(test)f(this)h(f)o(acility)-5 b(,)22
b(as)h(the)f(user)g(can)h(ensure)f(that)g(such)h(services)g(are)f
(operational)h(in)227 3056 y(his)f(home)g(domain.)32
b(An)22 b(outbound)h(proxy)g(in)e(the)h(visited)f(domain)i(can)f
(handle)g(the)g(call)f(if)g(it)g(belie)n(v)o(es)h(to)g(be)g(in)f(a)g
(position)i(to)227 3147 y(pro)o(vide)d(appropriate)g(emer)o(genc)o(y)g
(services.)141 3307 y Fl(In)k(addition,)h(we)e(reserv)o(e)i(user)f
(addresses)i(be)o(ginning)g(with)d(the)h(string)h(\223sos.)-6
b(\224)29 b(for)24 b(speci\002c)g(emer)n(genc)o(y)i(services:)50
3491 y(sos.\002re)323 b(\002re)23 b(brigade)50 3604 y(sos.rescue)214
b(amb)n(ulance)26 b(\(rescue\))50 3717 y(sos.marine)193
b(marine)24 b(guard)50 3830 y(sos.police)224 b(police)25
b(\(la)o(w)e(enforcement\))50 3943 y(sos.mountain)103
b(mountain)25 b(rescue)141 4125 y(The)c(sub-addresses)k(are)c(also)h
(case-insensiti)n(v)o(e.)32 b(Additional)23 b(subaddresses)i(can)d(be)f
(re)o(gistered)i(with)e(IAN)m(A)e(\(Sec-)0 4238 y(tion)24
b(11\).)339 4376 y Fk(In)19 b(some)h(areas,)f(these)g(emer)o(genc)o(y)h
(services)f(use)g(dif)n(ferent)g(numbers.)141 4536 y
Fl(The)j(SIP)e(URI)h(user)h(name)g(\223sos\224)h(and)g(user)f(names)g
(starting)i(with)e(\223sos.)-6 b(\224)31 b Fe(M)t(U)t(S)t(T)c(N)t(O)q
(T)d Fl(be)e(assigned)i(to)e(an)o(y)g(re)o(gular)0 4649
y(user)-5 b(.)0 4894 y Fi(3.2)99 b(T)-9 b(el)25 b(URIs)g(f)n(or)f(Emer)
o(gency)i(Calls)0 5068 y Fl(User)e(agents)k Fe(S)t(H)t(O)t(U)t(L)t(D)f
Fl(determine)g(the)d(local)i(emer)n(genc)o(y)g(numbers,)g(either)f(by)g
(consulting)i(their)e(manual)g(con\002gura-)0 5181 y(tion)e(for)g(de)n
(vices)i(that)e(do)g(not)g(mo)o(v)o(e)f(across)i(national)h(borders,)f
(by)f(DHCP)d(\(Section)k(9\))f(or)g(some)f(other)i(con\002guration)0
5294 y(mechanism.)30 b(If)22 b(a)g(user)h(agent)g(has)g(no)f(kno)n
(wledge)i(of)f(local)g(emer)n(genc)o(y)h(numbers,)g(it)g
Fe(M)t(U)t(S)t(T)i Fl(also)d(recognize)i(the)d(digit)0
5407 y(strings)j(000,)f(08,)f(112,)h(110,)g(118,)g(119,)g(911)g(and)g
(999)g(as)f(emer)n(genc)o(y)j(numbers.)0 5656 y Fk(H.)18
b(Schulzrinne)1239 b Fl(Expires)25 b(June)f(2003)1240
b([P)o(age)23 b(3])p eop
%%Page: 4 4
4 3 bop 0 100 a Fl(INTERNET)-8 b(-DRAFT)640 b(draft-schulzrinne-)q(sip)
q(pin)q(g-)q(sos)q(-04)q(.ps)629 b(January)25 b(8,)e(2003)339
399 y Fk(SIP)d(user)i(agents,)h(such)f(as)f(Ethernet)g(deskphones,)j
(that)e(are)f(unlik)o(ely)h(to)g(mo)o(v)o(e)g(frequently)g(across)g
(national)g(borders)g(can)227 490 y(easily)i(implement)g(a)g(local)g
(dialing)g(plan)g(that)f(recognizes)i(local)f(emer)o(genc)o(y)h
(numbers.)39 b(Mobile)24 b(de)n(vices,)h(including)g(PD)m(As)227
581 y(and)17 b(laptops,)g(may)g(not)g(ha)o(v)o(e)f(a)h(reliable)f(w)o
(ay)h(of)f(determining)h(their)f(current)h(location.)23
b(Using)16 b(automatic)h(con\002guration)h(a)o(v)o(oids)227
672 y(collisions)i(with)g(e)o(xtensions)h(that)e(equal)i(one)f(of)g
(the)g(eight)g(numbers)h(abo)o(v)o(e.)27 b(If)19 b(a)h(local)g(netw)o
(ork)h(does)f(not)g(ha)o(v)o(e)g(an)g(outbound)227 764
y(proxy)i(serv)o(er)m(,)g(local)f(dial)g(plans)g(also)h(do)f(not)h
(apply)-5 b(,)22 b(so)f(the)g(problem)h(of)f(number)h(collision)f(does)
h(not)g(arise.)29 b(Collisions)21 b(with)227 855 y(non-emer)o(genc)o(y)
d(service)e(numbers)h(are)f(still)f(possible,)i(albeit)f(less)f(lik)o
(ely)-5 b(.)23 b(F)o(or)15 b(e)o(xample,)i(118)g(is)e(used)i(for)f
(directory)g(assistance)227 946 y(in)j(the)g(United)g(Kingdom.)141
1108 y Fl(If)33 b(the)h(user)f(dials)h(an)o(y)g(of)f(these)h(digit)g
(strings,)j(the)d(U)l(A)l(C)g Fe(S)t(H)t(O)t(U)t(L)t(D)i
Fl(generate)f(a)e(request)i(with)e(the)g(\223sos\224)h(URI)0
1221 y(described)c(in)c(Section)i(3.1)f(unless)i(it)d(has)i(disco)o(v)o
(ered)h(a)e(local)h(outbound)h(proxy)g(as)e(described)i(in)e(Section)h
(9.)39 b(In)27 b(that)0 1334 y(case,)d(a)f(U)l(A)l(C)h
Fe(M)t(A)l(Y)i Fl(use)e(a)f(\223tel\224)h(URI)e([3)q(,)g(4)q(])h
(without)h Fh(phone-conte)m(xt)p Fl(,)d(such)k(as)0 1546
y Fc(tel:911)0 1659 y(tel:112)141 1872 y Fl(Outbound)d(proxy)f(serv)o
(ers)j Fe(M)t(U)t(S)t(T)f Fl(be)d(con\002gurable)j(to)d(recognize)j
(additional)g(local)e(emer)n(genc)o(y)h(numbers)f(in)f(\223tel\224)0
1984 y(URIs.)339 2124 y Fk(There)h(are)g(about)h(60)f(service)g
(numbers)h(for)f(emer)o(genc)o(y)g(services)h(in)e(the)h(w)o(orld;)h
(including)g(them)f(all)f(is)g(not)i(practical,)e(as)227
2215 y(that)f(w)o(ould)h(interfere)f(with)f(e)o(xisting)h(local)g(tw)o
(o,)g(three)g(and)g(four)o(-digit)g(dialing)g(plans.)0
2505 y Fj(4)119 b(Request)31 b(Handling)0 2712 y Fl(Once)25
b(identi\002ed,)j(a)d(user)h(agent)i Fe(S)t(H)t(O)t(U)t(L)t(D)h
Fl(direct)d(an)g(emer)n(genc)o(y)h(call)f(request)h(to)f(an)f(outbound)
j(proxy)f(serv)o(er)f(or)g(use)0 2825 y(the)e(disco)o(v)o(ery)h
(mechanism)g(described)h(in)d(Section)h(9)f(to)h(\002nd)f(a)g(local)h
(PSTN)d(gate)n(w)o(ay)j(that)g(can)g(connect)h(the)f(caller)g(to)0
2938 y(a)f(local)i(emer)n(genc)o(y)g(call)f(center)-5
b(.)141 3051 y(Outbound)28 b(proxy)f(serv)o(ers)i Fe(M)t(U)t(S)t(T)g
Fl(recognize)f(all)e(local)h(emer)n(genc)o(y)g(numbers)g(as)f(well)g
(as)f(the)h(tel)g(URIs)f(enumer)n(-)0 3164 y(ated)30
b(in)f(Section)h(3.2.)46 b(The)29 b(proxy)j Fe(M)t(A)l(Y)f
Fl(use)f(an)o(y)f(additional)j(information)g(contained)g(in)d(the)g
(call)h(request,)i(such)e(as)0 3276 y(Mobile)25 b(Country)g(Code)f(and)
g(the)g(Mobile)h(Netw)o(ork)f(Code)g(for)g(3GPP)e(de)n(vices,)j(to)f
(recognize)i(additional)h(numbers)e(as)0 3389 y(emer)n(genc)o(y)h
(numbers.)141 3502 y(It)d(is)j Fe(R)t(E)t(C)t(O)t(M)t(M)t(E)t(N)t(D)t
(E)t(D)h Fl(that)e(gate)n(w)o(ay)f(SIP)e Fh(MESSA)m(GE)e
Fl(requests)26 b(are)d(directed)j(to)d(a)g(TTY)-10 b(-for)n(-the-deaf)
26 b(transla-)0 3615 y(tor)e(or)f(a)g(short-message)k(service)e
(\(SMS\))d(if)i(the)g(emer)n(genc)o(y)h(call)f(center)h(cannot)g
(handle)g(SIP)d(instant)j(messaging.)339 3755 y Fk(Using)18
b(a)g(proxy)h(serv)o(er)f(that)f(is)g(local)h(to)g(the)f(user)h(agent)h
(is)e(more)h(lik)o(ely)g(to)f(reach)i(a)e(geographically)j(local)d
(serv)o(er)m(,)h(although)227 3846 y(that)h(is)g(not)g(guaranteed)h(if)
f(virtual)f(pri)n(v)n(ate)i(netw)o(orks)g(are)e(being)i(used.)141
4007 y Fl(User)37 b(agent)h(serv)o(ers)h(and)e(proxy)i(serv)o(ers)h
Fe(M)t(U)t(S)t(T)i(N)t(O)q(T)e Fl(require)e(that)g(the)f(user)h(agent)g
(client)h(be)e(re)o(gistered)i(or)0 4120 y(authenticated)27
b(in)d(order)g(to)g(place)g(an)g(emer)n(genc)o(y)i(call.)141
4233 y Fh(OPTIONS)d Fl(requests)k(to)f(the)f(user)h(\223sos\224)h(and)f
(the)f(\223sos.*\224)i(addresses)h(\(sos.\002re,)e(etc.\))34
b(can)26 b(be)g(used)g(to)f(test)h(if)f(the)0 4346 y(\223sos\224)d
(addresses)h(are)f(v)n(alid.)28 b(As)20 b(in)h(standard)i(SIP)-10
b(,)19 b(a)i(200)g(\(OK\))f(response)j(indicates)g(that)f(the)f
(address)i(w)o(as)d(recognized)0 4459 y(and)25 b(a)f(404)h(\(Not)f
(found\))i(that)f(it)g(w)o(as)f(not.)32 b(Such)24 b(request)i(cause)g
(no)e(further)i(action.)33 b(It)24 b(is)j Fe(R)t(E)t(C)t(O)t(M)t(M)t(E)
t(N)t(D)t(E)t(D)i Fl(that)c(user)0 4572 y(agents)32 b(periodically)h
(automatically)h(check)d(for)f(the)h(a)n(v)n(ailability)i(of)d(the)h
(\223sos\224)g(identi\002er)h(and)f(alert)g(the)f(user)h(if)f(the)0
4685 y(check)i(f)o(ails.)50 b(The)29 b(period)j(of)f(such)g(automated)h
(checks)i Fe(S)t(H)t(O)t(U)t(L)t(D)h(N)t(O)q(T)e Fl(be)d(less)h(than)g
(once)g(per)g(day)g(and)i Fe(M)t(U)t(S)t(T)g Fl(be)0
4798 y(randomly)25 b(placed)g(o)o(v)o(er)f(the)g(testing)h(interv)n
(al.)0 5087 y Fj(5)119 b(Determining)31 b(User)f(Agent)h(Location)0
5294 y Fl(Proper)26 b(handling)h(of)e(emer)n(genc)o(y)i(calls)f
(requires)h(kno)n(wledge)f(of)f(the)h(caller)g(location)h(to)e(route)h
(the)f(call)h(to)e(the)i(appro-)0 5407 y(priate)j(ECC)d(and)i(to)f
(help)i(the)f(ECC)d(in)j(locating)i(the)e(caller)h(when)e(rendering)k
(emer)n(genc)o(y)e(assistance.)44 b(W)-7 b(e)27 b(describe)0
5656 y Fk(H.)18 b(Schulzrinne)1239 b Fl(Expires)25 b(June)f(2003)1240
b([P)o(age)23 b(4])p eop
%%Page: 5 5
5 4 bop 0 100 a Fl(INTERNET)-8 b(-DRAFT)640 b(draft-schulzrinne-)q(sip)
q(pin)q(g-)q(sos)q(-04)q(.ps)629 b(January)25 b(8,)e(2003)0
399 y(the)h(routing)h(details)g(in)f(Section)g(6.)141
511 y(The)31 b(SIP)f(U)l(A)g(determines)k(its)d(location,)k(preferably)
g(ahead)d(of)f(the)h(emer)n(genc)o(y)h(call.)53 b(It)33
b Fe(M)t(A)l(Y)g Fl(use)f(DHCP)d([9)q(],)0 624 y(retrie)n(ving)24
b(the)d(the)h(location)h(one)f(or)f(more)g(of:)28 b(geospatial)c
(coordinates)h(\(longitude,)f(latitude)f(and)f(altitude\))i([10)q(],)d
(ci)n(vil)0 737 y(address)29 b(\(street)f(and)f(community\))i([11)q(])d
(or)h(netw)o(ork)h(access)g(information)i(such)d(as)g(the)g(port)h(and)
f(switch)g(number)h(or)0 850 y(the)c(wireless)g(cell)g(identity)-6
b(.)141 963 y(The)25 b(U)l(A)f(needs)j(to)e(inform)h(the)g(DHCP)d(serv)
o(er)j(about)h(its)f(netw)o(ork)g(attachment)i(point.)35
b(There)26 b(are)f(se)n(v)o(eral)i(possi-)0 1076 y(bilities,)22
b(including)g(use)f(of)e(the)h(RFC)e(3046)j([12)q(])e(Agent-Circuit-ID)
j(or)e(Remote-ID)g(sub-options.)31 b(This)19 b(approach)k(will)0
1189 y(only)j(w)o(ork)f(if)f(the)i(DHCP)c(relay)k(agent)g(is)f
(colocated)i(with)e(the)g(LAN)e(de)n(vice)j(close)g(to)f(the)g(SIP)e(U)
l(A.)h(Another)i(option,)0 1302 y(not)d(yet)f(fully)h(supported,)i(is)d
(to)g(ha)n(v)o(e)h(the)g(U)l(A)e(determine)j(the)e(de)n(vice)i(and)e
(port)h(information)i(and)e(then)f(include)j(this)d(in)0
1415 y(the)i(DHCP)d(request.)30 b(There)24 b(currently)i(is)d(no)h
(DHCP)d(option)k(for)f(doing)h(so,)e(ho)n(we)n(v)o(er)-5
b(.)141 1528 y(The)35 b(U)l(A)l(C)f(inserts)i(this)g(location)h(into)f
(a)e(SIP)g(header)j(\002eld.)63 b(F)o(or)34 b(geographic)k
(information,)i(this)c(might)f(look)0 1641 y(something)26
b(lik)o(e)e(the)g(follo)n(wing:)0 1878 y Fc(Location:)50
b(;lat=38.89868)f(;long=-77.03723)f(;alt=15)j(;alt-unit=m)109
1991 y(;lares=0.000122)d(;lores=0.00012)o(2)109 2104
y(;hno=600)j(;lmk="White)f(House")h(;mcn="Washington)o(")109
2217 y(;stn="Pennsylva)o(ni)o(a")d(;sts="Ave")i(;sta="DC")109
2330 y(;privacy=dnf)0 2567 y Fl(Here,)23 b(we)g(assume)h(that)g(the)g
(DHCP)d(option)k(pro)o(vided)h(a)d(resolution)j(of)e(22)f(bits.)30
b(The)23 b(e)o(xample)h(is)g(tak)o(en)g(from)g([13)q(].)141
2680 y(\(The)f(SIP)g(header)i(\002eld)e(format)h(is)f(\002ctitious)i
(and)f(is)g(de\002ned)g(in)g(TBD.\))141 2793 y(F)o(or)h(3GPP)e(netw)o
(orks,)28 b(the)d Fh(P-Access-Netw)o(or)q(k-Inf)m(o)h
Fl(header)h(\002eld)e([14)q(])g(can)h(con)l(v)o(e)o(y)h(the)e(cell)h
(information,)i(as)0 2906 y(de\002ned)c(in)g(3GPP)e(TS)g(24.229.)141
3019 y(Alternati)n(v)o(ely)-6 b(,)24 b(an)e(outbound)i(proxy)f(may)e
(map)g(the)h(U)l(A)-10 b(')-5 b(s)21 b(de)n(vice)i(address)g(to)f(a)f
(physical)i(location,)h(e.g.,)d(based)i(on)0 3132 y(a)g(traceback)j
(within)e(an)g(Ethernet)g(switched)h(LAN.)d(Such)h(mechanisms)i(are)f
(be)o(yond)h(the)f(scope)h(of)e(this)h(document.)0 3424
y Fj(6)119 b(Request)31 b(Routing)0 3631 y Fl(An)o(y)f(proxy)-6
b(,)33 b(outbound)g(or)d(otherwise,)j(that)e(recei)n(v)o(es)h(such)f(a)
f(request)k Fe(M)t(U)t(S)t(T)g Fl(forw)o(ard)d(\(proxy\))h(or)e
(redirect)i(the)f(re-)0 3744 y(quest)e(to)f(the)g(appropriate)k(emer)n
(genc)o(y)e(number)f(local)g(to)f(the)g(caller)l(,)i(using)g(the)e
(location)i(information)h(described)f(in)0 3857 y(Section)24
b(5.)141 3970 y(Note)19 b(that)h(in)f(some)g(limited)h(cases,)h(the)e
(proxy)i(may)e(be)g(able)h(to)f(determine)i(that)f(the)f(requestor)j
(is)d(in)g(the)g(same)g(local)0 4083 y(netw)o(ork)31
b(e)n(v)o(en)g(without)g(e)o(xplicit)g(location)i(information.)51
b(This)30 b(may)g(be)g(the)g(case,)i(for)f(e)o(xample,)h(if)e(the)g(IP)
f(address)0 4196 y(of)c(the)g(request)i(indicates)g(a)e(local)h(de)n
(vice)g(and)g(the)f(netw)o(ork)h(of)n(fers)g(no)f(VPN)f(services.)35
b(Ev)o(en)24 b(under)j(these)f(restricted)0 4309 y(circumstances,)g
(back-to-back)i(U)l(As)22 b(may)i(mislead)g(the)g(proxy)h(in)e(this)h
(estimation.)141 4422 y(W)-7 b(e)30 b(distinguish)k(tw)o(o)d(cases,)i
(depending)h(on)c(whether)i(the)f(proxy)h(has)g(access)g(to)e(a)h
(location-to-ECC)i(mapping)0 4534 y(service)25 b(or)f(not.)29
b(A)22 b(special,)j(b)n(ut)f(important,)h(case)f(is)g(that)g(the)g
(caller)g(is)g(kno)n(wn)f(to)h(be)f(local)i(to)e(a)g(PSTN)e(gate)n(w)o
(ay)-6 b(.)0 4784 y Fi(6.1)99 b(Kno)o(wn)25 b(to)g(be)h(Local)0
4958 y Fl(In)h(some)g(cases,)h(the)f(proxy)h(serv)o(er)g(can)f
(reliably)i(determine)f(that)f(the)h(caller)f(and)h(a)e(local)i(PSTN)c
(gate)n(w)o(ay)j(are)g(in)g(the)0 5071 y(same)i(emer)n(genc)o(y)h
(service)g(area.)45 b(In)28 b(that)i(case,)g(the)f(proxy)g(forw)o(ards)
h(the)f(call)g(request)i(to)d(the)h(gate)n(w)o(ay)-6
b(,)30 b(translating)0 5184 y(the)24 b(emer)n(genc)o(y)h(URI)e(into)h
(the)g(local)g(emer)n(genc)o(y)i(number)-5 b(.)0 5656
y Fk(H.)18 b(Schulzrinne)1239 b Fl(Expires)25 b(June)f(2003)1240
b([P)o(age)23 b(5])p eop
%%Page: 6 6
6 5 bop 0 100 a Fl(INTERNET)-8 b(-DRAFT)640 b(draft-schulzrinne-)q(sip)
q(pin)q(g-)q(sos)q(-04)q(.ps)629 b(January)25 b(8,)e(2003)0
399 y Fi(6.2)99 b(Mapping)26 b(Ser)o(vice)f(A)-10 b(v)o(ailable)0
573 y Fl(W)j(e)28 b(refer)j(to)e(the)g(location-to-ECC)j(mapping)f
(service)g(as)e(a)g(jurisdictional)k(directory)f(service)f(\(JDS\))e
(since)h(it)f(maps)0 686 y(geographic)e(and/or)e(ci)n(vil)f(locations)j
(to)c(emer)n(genc)o(y)j(response)g(jurisdictions.)33
b([TBD:)22 b(better)j(term?])30 b(The)24 b(JDS)e(can)i(be)0
799 y(considered)31 b(a)d(special)i(kind)f(of)f(SIP)f(location)j
(service.)44 b(The)28 b(protocol)i(between)g(the)e(proxy)i(and)e(the)h
(JDS)e(is)h(be)o(yond)0 912 y(the)c(scope)h(of)e(this)h(document.)339
1061 y Fk(One)c(plausible)f(solution)h(simply)f(proxies)g(the)g(SIP)f
(request)h(itself)g(to)f(the)h(JDS.)141 1232 y Fl(Conceptually)-6
b(,)23 b(the)d(JDS)f(is)g(pro)o(vided)i(with)f(a)f(geographic)k
(location)e(and)f(possibly)i(the)e(type)g(of)g(emer)n(genc)o(y)i
(service)0 1345 y(requested)g(\(for)e(\223sip:sos.service\224)j(URIs\))
c(and)h(returns)h(SIP)c(or)j(tel)f(URIs)f(for)i(one)f(or)h(more)f(ECCs)
e(serving)22 b(the)d(caller)-5 b(.)28 b(If)0 1458 y(the)c(JDS)f(does)i
(not)f(recognize)j(the)d(service)i(speci\002cation,)h(it)c(treats)j
(the)e(mapping)h(request)h(lik)o(e)f(a)e(general)j(emer)n(genc)o(y)0
1571 y(service)f(request.)141 1684 y(The)19 b(tel)g(URI)e(returned)k
(by)e(the)h(JDS)d(will)i(contain)h(a)f(globally)i(reachable)g
(\(E.164\))f(number)l(,)h(i.e.,)d(a)h Fh(global-n)o(umber)0
1797 y Fl(according)i(to)d([4)q(].)26 b(The)18 b(proxy)i(routes)g(the)e
(call)h(accordingly)-6 b(,)23 b(using)c(a)f(local)h(mechanism)h(to)e
(determine)i(the)f(appropriate)0 1909 y(gate)n(w)o(ay)-6
b(,)24 b(e.g.,)f(TRIP)e([5)q(].)339 2059 y Fk(Ideally)-5
b(,)29 b(the)d(chosen)i(gate)n(w)o(ay)f(should)h(be)f(local)f(to)g(the)
h(ECC,)e(b)o(ut)h(that)h(may)g(not)f(be)h(achie)n(v)n(able,)j(as)c(it)g
(w)o(ould)h(require)227 2150 y(a)e(gate)n(w)o(ay)g(in)g(e)n(v)o(ery)g
(community)-5 b(.)42 b(In)25 b(the)f(United)h(States,)g(for)g(e)o
(xample,)i(there)d(are)h(about)g(5,000)h(primary)f(emer)o(genc)o(y)h
(call)227 2242 y(centers,)19 b(called)g(Public)g(Safety)g(Answering)g
(Points)g(\(PSAPs\).)0 2491 y Fi(6.3)99 b(No)25 b(Mapping)g(Ser)o(vice)
h(A)-10 b(v)o(ailable)0 2665 y Fl(If)33 b(the)g(proxy)h(does)f(not)h
(ha)n(v)o(e)f(access)h(to)f(a)f(JDS,)f(it)i(attempts)h(to)f(pick)g(the)
g(closest)i(PSTN)30 b(gate)n(w)o(ay)-6 b(,)36 b(translates)f(the)0
2778 y(Request-URI)24 b(to)g(a)f(locally)i(v)n(alid)f(emer)n(genc)o(y)i
(number)e(and)g(proxies)i(the)e(call)g(to)f(that)h(gate)n(w)o(ay)-6
b(.)141 2891 y(If)18 b(a)g(proxy)h(recei)n(v)o(es)g(a)f
(service-speci\002c)k(request)e(of)e(the)g(form)g
(\223sip:sos.*@domain\224)k(\(such)d(as)f(\223sos.\002re@e)o
(xample.com\224\),)0 3004 y(the)25 b(proxy)h(forw)o(ards)g(it)f(to)f
(the)h(local)h(appropriate)i(speci\002c)e(emer)n(genc)o(y)g(service.)34
b(If)25 b(it)f(does)i(not)f(recognize)i(the)e(suf)n(\002x)0
3117 y(\(e.g.,)d(\223\002re\224\),)h(it)i Fe(M)t(U)t(S)t(T)h
Fl(forw)o(ard)e(the)f(request)h(to)f(the)g(appropriate)j(general)f
(emer)n(genc)o(y)g(contact,)f(handling)h(it)e(as)f(if)h(the)0
3230 y(address)i(w)o(as)f(\223sip:sos@domain\224.)0 3522
y Fj(7)119 b(Caller)31 b(Identi\002cation)0 3729 y Fl(When)36
b(using)h(a)e(PSTN)f(gate)n(w)o(ay)-6 b(,)39 b(the)d(gate)n(w)o(ay)g
(causes)i(the)e(calling)h(number)g(to)f(be)f(a)h(telephone)i(number)f
(that)f(is)0 3842 y(mapped)31 b(by)g(the)f(ECC)f(to)h(the)h(location)h
(of)e(the)h(caller)-5 b(.)50 b(\(The)31 b(process)h(for)e(creating)j
(such)e(mappings)h(is)e(be)o(yond)i(the)0 3955 y(scope)c(of)f(this)g
(document.)41 b(The)26 b(process)j(has)f(been)f(demonstrated)j(in)d
(some)g(jurisdictions)k(for)c(multi-line)i(telephone)0
4068 y(systems.\))41 b(It)27 b(is)h(not)f(clear)h(whether)h(all)e
(circuit-switched)k(trunk)e(technologies)i(allo)n(w)c(potentially)j
(arbitrary)-6 b(,)31 b(out-of-)0 4181 y(area)24 b(calling)h(numbers.)0
4473 y Fj(8)119 b(Call)31 b(Beha)m(vior)0 4680 y Fl(The)23
b(user)h(agent)j Fe(S)t(H)t(O)t(U)t(L)t(D)f Fl(not)e(issue)h(a)e
Fh(REFER)e Fl(during)k(an)e(emer)n(genc)o(y)j(call.)141
4793 y(The)g(user)h(agent)i Fe(S)t(H)t(O)t(U)t(L)t(D)i(N)t(O)q(T)d
Fl(issue)g(a)d Fh(BYE)g Fl(request)i(during)h(an)e(emer)n(genc)o(y)i
(call.)38 b(If)25 b(the)i(user)g(\223hangs)g(up\224,)g(it)0
4906 y(is)e Fe(R)t(E)t(C)t(O)t(M)t(M)t(E)t(N)t(D)t(E)t(D)j
Fl(that)c(the)g(end)g(system)g(generate)i(an)e(alert)g(tone)g(until)h
(the)e(user)i(reconnects.)141 4998 y(The)d(U)l(A)h Fe(S)t(H)t(O)t(U)t
(L)t(D)i Fl(automatically)h(accept)e(an)e(incoming)i(call)f(from)f(the)
g(same)h(entity)g(that)g(accepted)i(the)d(pre)n(vious)0
5089 y(emer)n(genc)o(y)k(call.)339 5213 y Fk(This)19
b(allo)n(ws)g(the)g(ECC)f(to)h(call)f(back)i(should)g(the)f(call)f(be)i
(interrupted)f(accidentally)-5 b(.)0 5656 y(H.)18 b(Schulzrinne)1239
b Fl(Expires)25 b(June)f(2003)1240 b([P)o(age)23 b(6])p
eop
%%Page: 7 7
7 6 bop 0 100 a Fl(INTERNET)-8 b(-DRAFT)640 b(draft-schulzrinne-)q(sip)
q(pin)q(g-)q(sos)q(-04)q(.ps)629 b(January)25 b(8,)e(2003)0
399 y Fj(9)119 b(Identifying)31 b(the)f(Local)g(Emer)o(gency)f(Numbers)
h(and)h(Gateway)0 606 y Fl(There)e(are)g(man)o(y)f(w)o(ays)h(that)g(a)f
(user)h(agent)h(can)f(con\002gure)h(emer)n(genc)o(y)g(numbers)g(for)f
(use)g(in)f(analyzing)k(calls)d(made)0 718 y(with)23
b(telephon)o(y-type)k(user)d(input.)29 b(These)24 b(include)h
(con\002guration)h(tok)o(ens)e(such)g(as)f(SIM)f(cards)i(in)f(mobile)h
(de)n(vices,)g(or)0 831 y(protocol-based)31 b(solutions.)40
b(W)-7 b(e)26 b(describe)i(one)f(such)h(protocol-based)j(mechanism,)d
(based)g(on)e(DHCP)-10 b(,)24 b(b)n(ut)j(this)g(does)0
944 y(not)d(imply)g(a)f(requirement)j(for)e(de)n(vices.)141
1057 y(W)-7 b(e)23 b(propose)j(a)d(ne)n(w)g(DHCP)f(option)j(that)f
(enumerates)i(the)e(v)n(alid)h(local)g(emer)n(genc)o(y)g
(identi\002ers,)h(as)d(a)h(list)g(of)g(\223tel\224,)0
1170 y(\223sip\224)32 b(or)g(\223sips\224)g(URIs.)51
b(These)32 b(identi\002ers)h(can)f(be)f(used)h(by)g(the)f(U)l(A)g(to)g
(trigger)i(special)g(beha)n(vior)h(when)d(the)h(user)0
1283 y(dials)d(those)f(numbers,)i(or)e(the)o(y)g(can)g(identify)h(a)e
(local)i(PSTN)c(gate)n(w)o(ay)j(that)g(can)g(pro)o(vide)i(local)e(emer)
n(genc)o(y)i(service.)0 1396 y(A)d(DHCP)e(serv)o(er)31
b Fe(S)t(H)t(O)t(U)t(L)t(D)g Fl(adv)o(ertise)f(its)e(local)h(emer)n
(genc)o(y)g(number)g(as)f(well)g(as)f(those)i(numbers)h(among)e(the)g
(eight)0 1509 y(digit)c(strings)i(enumerated)f(in)f(Section)g(3.2)g
(that)g(do)f(not)h(collide)i(with)d(local)h(non-emer)n(genc)o(y)k
(services)d(or)f(e)o(xtensions.)141 1622 y(This)f(DHCP)f(option)27
b Fe(M)t(U)t(S)t(T)h(N)t(O)q(T)e Fl(be)e(used)g(if)f(DHCP)f(does)i(not)
g(announce)i(the)e(local)g(SIP)e(serv)o(er)j([6].)339
1756 y Fk(Unlik)o(e)k(an)g(outbound)i(proxy)f(serv)o(er)m(,)g(the)f
(DHCP)f(serv)o(er)g(is)h(v)o(ery)g(lik)o(ely)f(to)h(be)g(located)g
(within)f(the)h(same)g(country)g(as)227 1847 y(the)c(user)g(agent.)42
b(Ho)n(we)n(v)o(er)m(,)27 b(since)e(the)g(user)g(agent)g(needs)h(to)f
(perform)g(the)g(call)g(routing,)h(it)f(mak)o(es)g(little)f(sense)i(to)
e(ha)o(v)o(e)h(the)227 1939 y(DHCP)20 b(information)i(identify)f(a)g
(set)g(of)g(numbers)i(that)d(mean)i(nothing)g(special)g(to)f(the)g
(outbound)i(proxy)f(serv)o(er)l(.)30 b(Thus,)21 b(serv)o(er)227
2030 y(identi\002cation)e(and)h(emer)o(genc)o(y)g(number)g
(identi\002cation)f(belong)h(together)l(.)141 2186 y
Fl(If)32 b(the)h(local)g(netw)o(ork)g(supports)i(the)d(location)j(of)d
(gate)n(w)o(ays)h(via)g(SLP)d([7],)k(the)f(user)g(agent)g(can)g(disco)o
(v)o(er)g(such)0 2299 y(gate)n(w)o(ays.)d(The)23 b(SLP)e(service)k
(description)i(needs)e(to)e(be)h(enhanced)i(with)d(a)g(list)h(of)f(v)n
(alid)i(emer)n(genc)o(y)g(numbers.)141 2412 y(Details)f(are)g
(described)i(in)e(TBD.)141 2525 y([This)g(is)f(for)h(discussion)i(only)
f(and,)e(if)h(suitable,)h(will)e(mo)o(v)o(e)g(to)h(a)f(dif)n(ferent)i
(draft.])0 2813 y Fj(10)119 b(Alter)n(nati)o(v)o(e)30
b(Identi\002ers)h(Consider)n(ed)0 3020 y Fl(The)g(\223sos\224)i(SIP)d
(URI)h(reserv)o(ed)i(user)g(name)e(proposed)k(here)d(follo)n(ws)g(the)g
(con)l(v)o(ention)j(of)d(RFC)e(2142)i([15)r(])f(and)h(the)0
3133 y(\223postmaster\224)d(con)l(v)o(ention)h(documented)f(in)d(RFC)e
(2822)k([16)q(].)36 b(One)26 b(dra)o(wback)i(is)e(that)h(it)f(may)g
(con\003ict)h(with)g(locally)0 3245 y(assigned)f(addresses)g(of)d(the)h
(form)g(\223sos@some)n(where\224.)141 3358 y(There)g(are)g(a)f(number)h
(of)g(possible)h(alternati)n(v)o(es,)h(each)e(with)g(their)g(o)n(wn)f
(set)h(of)f(adv)n(antages)k(and)d(problems:)0 3541 y
Fb(tel:sos)48 b Fl(This)20 b(solution)i(a)n(v)n(oids)h(name)d
(con\003icts,)i(b)n(ut)f(is)f(not)h(a)f(v)n(alid)h(\223tel\224)g(URI.)e
(It)h(also)h(only)g(w)o(orks)g(if)f(e)n(v)o(ery)h(outbound)227
3654 y(proxy)38 b(kno)n(ws)e(ho)n(w)f(to)h(route)h(requests)h(to)e(a)f
(proxy)j(that)e(can)h(reach)f(emer)n(genc)o(y)i(services.)68
b(The)36 b(SIP)e(URI)227 3767 y(proposed)26 b(here)e(only)h(requires)g
(a)e(user')-5 b(s)25 b(home)f(domain)g(to)g(be)f(appropriately)28
b(con\002gured.)0 3944 y Fb(URI)22 b(parameter:)48 b
Fl(One)30 b(could)h(create)h(a)e(special)i(URI,)c(such)k(as)e(\223aor)n
(-domain;user=sos)q(\224.)54 b(This)30 b(a)n(v)n(oids)j(the)d(name)227
4057 y(con\003ict)e(problem,)g(b)n(ut)f(requires)i(mechanism-a)o(w)o
(are)g(user)e(agents)h(that)g(are)e(capable)j(of)d(emitting)i(this)g
(special)227 4170 y(URI.)0 4348 y Fb(Special)c(domain:)45
b Fl(A)27 b(special)j(domain,)g(such)f(as)f(\223sip:\002re@sos.int\224)
k(could)d(be)f(used)h(to)f(identify)i(emer)n(genc)o(y)h(calls.)227
4461 y(This)24 b(has)g(similar)g(properties)i(as)e(the)f
(\223tel:sos\224)j(URI,)c(e)o(xcept)j(that)f(it)f(is)h(indeed)h(a)e(v)n
(alid)h(URI.)0 4749 y Fj(11)119 b(IAN)n(A)30 b(Considerations)0
4956 y Fl(Subaddresses)e(of)c(the)h(\223sos\224)h(address)h(are)e(re)o
(gistered)i(with)d(IAN)m(A)f(This)i(speci\002cation)i(establishes)h
(the)d(\223sos\224)h(subad-)0 5068 y(dres)e(sub-re)o(gistry)j(under)e
(http://www)-6 b(.iana.or)n(g/assignment)q(s/s)q(ip-)q(par)q(amete)q
(rs.)141 5181 y(Subaddresses)28 b(are)d(re)o(gistered)i(by)e(the)g(IAN)
m(A)e(when)i(the)o(y)g(are)g(published)i(in)e(standards)i(track)f
(RFCs.)31 b(The)24 b(IAN)m(A)0 5294 y(Considerations)38
b(section)e(of)f(the)f(RFC)f(must)h(include)j(the)d(follo)n(wing)i
(information,)k(which)35 b(appears)h(in)e(the)h(IAN)m(A)0
5407 y(re)o(gistry)25 b(along)g(with)e(the)h(RFC)e(number)i(of)f(the)h
(publication.)0 5656 y Fk(H.)18 b(Schulzrinne)1239 b
Fl(Expires)25 b(June)f(2003)1240 b([P)o(age)23 b(7])p
eop
%%Page: 8 8
8 7 bop 0 100 a Fl(INTERNET)-8 b(-DRAFT)640 b(draft-schulzrinne-)q(sip)
q(pin)q(g-)q(sos)q(-04)q(.ps)629 b(January)25 b(8,)e(2003)136
399 y Fd(\017)46 b Fl(Name)33 b(of)h(the)g(subaddress.)62
b(The)34 b(name)i Fe(M)t(A)l(Y)f Fl(be)f(of)f(an)o(y)h(length,)k(b)n
(ut)e Fe(S)t(H)t(O)t(U)t(L)t(D)h Fl(be)c(no)h(more)g(than)h(twenty)227
511 y(characters)26 b(long.)k(The)23 b(name)j Fe(M)t(U)t(S)t(T)g
Fl(consist)g(of)d(alphanumeric)k(characters)f(only)e(and)g(is)g
(case-insensiti)n(v)o(e.)136 699 y Fd(\017)46 b Fl(Descripti)n(v)o(e)25
b(te)o(xt)f(that)g(describes)i(the)e(emer)n(genc)o(y)i(service.)0
992 y Fj(12)119 b(Security)31 b(Considerations)0 1199
y Fl(The)j(SIP)f(speci\002cation)38 b([1)q(])c(details)i(a)e(number)i
(of)f(security)h(considerations.)67 b(Security)36 b(for)f(emer)n(genc)o
(y)h(calls)g(has)0 1312 y(con\003icting)f(goals,)h(namely)d(to)g(mak)o
(e)g(it)f(as)h(easy)h(and)f(reliable)h(as)f(possible)i(to)e(reach)g
(emer)n(genc)o(y)i(services,)i(while)0 1424 y(discouraging)29
b(and)e(possibly)h(tracing)f(prank)g(calls.)36 b(It)25
b(appears)j(unlik)o(ely)g(that)e(classical)i(authentication)i
(mechanisms)0 1537 y(can)20 b(be)g(required)i(by)e(emer)n(genc)o(y)i
(call)f(centers,)h(b)n(ut)e(SIP)f(proxy)i(serv)o(ers)g(may)f(be)g(able)
h(to)e(add)i(identifying)i(information.)141 1650 y(Gi)n(v)o(en)36
b(the)g(sensiti)n(v)o(e)h(nature)g(of)f(man)o(y)f(emer)n(genc)o(y)j
(calls,)i(it)35 b(is)h(desirable)i(to)d(use)h(the)g(\223sips\224)i(URI)
c(to)i(ensure)0 1763 y(transport-le)n(v)o(el)27 b(con\002dentiality)g
(and)d(inte)o(grity)-6 b(.)31 b(Ho)n(we)n(v)o(er)l(,)23
b(this)h(may)f(cause)i(the)f(call)g(to)f(f)o(ail)h(in)g(some)f(en)l
(vironments.)141 1876 y(Allo)n(wing)31 b(the)g(user)g(agent)h(to)e
(clearly)j(and)e(unambiguously)j(identify)f(emer)n(genc)o(y)f(calls)g
(mak)o(es)f(it)f(possible)j(for)0 1989 y(the)23 b(user)g(agent)h(to)f
(mak)o(e)f(appropriate)k(polic)o(y)e(decisions.)31 b(F)o(or)22
b(e)o(xample,)h(a)f(user)i(agent)g(polic)o(y)f(may)g(re)n(v)o(eal)g(a)f
(dif)n(ferent)0 2102 y(amount)k(of)f(information)i(to)e(the)g(callee)i
(when)e(making)g(an)g(emer)n(genc)o(y)i(call.)34 b(Local)25
b(la)o(ws)g(may)f(af)n(fect)i(what)f(informa-)0 2215
y(tion)c(netw)o(ork)h(serv)o(ers)g(or)f(service)h(pro)o(viders)h(may)d
(be)h(allo)n(wed)g(or)f(be)h(required)i(to)d(release)j(to)d(emer)n
(genc)o(y)j(call)e(centers.)0 2328 y(The)o(y)i(may)g(also)i(base)f
(their)g(decision)i(on)e(the)f(user)n(-declared)28 b(destination)f(of)c
(the)h(call.)141 2441 y(Outbound)h(proxies)h(may)d(need)h(to)g(adjust)h
(their)f(authentication)k(requirements)e(for)e(such)g(emer)n(genc)o(y)i
(calls.)141 2554 y(It)35 b(is)f(desirable)k(to)d(be)f(able)i(to)f(v)o
(erify)h(that)f(the)g(call)h(is)e(reaching)j(a)e(true)g(emer)n(genc)o
(y)i(call)f(center)-5 b(.)64 b(The)34 b(caller)0 2666
y(is)k(unlik)o(ely)i(to)e(kno)n(w)g(or)g(be)g(able)g(to)g(obtain)h(the)
g(public)g(k)o(e)o(y)f(of)g(the)g(destination)j(ECC)36
b(since)j(it)f(does)h(not)f(e)n(v)o(en)0 2779 y(kno)n(w)32
b(the)g(ECC)e(identity)-6 b(.)55 b(The)32 b(responding)j(ECC)30
b(could)j(sign)f(the)g(response,)k(via)c(standard)i(SIP)d(S/MIME)f
(mech-)0 2892 y(anisms.)38 b(Ho)n(we)n(v)o(er)l(,)27
b(the)g(principal)i(in)d(the)h(certi\002cate)h(w)o(ould)f(appear)h(as)f
(a)f(random-looking)k(domain)e(name,)f(such)g(as)0 3005
y Fc(admin.fayette.c)o(o.)o(ga)o(.u)o(s)p Fl(,)21 b(which)27
b(cannot)i(be)e(reliably)i(identi\002ed)f(as)f(an)g(ECC.)e(Here,)i(an)g
(attrib)n(ute)j(certi\002-)0 3118 y(cate)20 b(\(A)l(C\))f([17)r(])g
(could)i(be)e(used)i(to)e(associate)k(the)c(attrib)n(ute)k(\223ECC\224)
18 b(with)i(the)g(SIP)e(URI.)g(Ho)n(we)n(v)o(er)l(,)i(it)f(appears)j
(unlik)o(ely)0 3231 y(that)31 b(such)f(an)h(Attrib)n(ute)g(Authority)h
(will)e(emer)n(ge)h(an)o(ytime)g(soon,)h(particularly)h(across)f
(national)g(borders.)50 b(Alterna-)0 3344 y(ti)n(v)o(ely)-6
b(,)28 b(ICANN)d(could)j(create)g(a)f(ne)n(w)f(restricted)k(top-le)n(v)
o(el)e(domain,)h(such)e(as)g(.sos,)h(that)f(is)g(open)h(only)g(to)e
(accredited)0 3457 y(emer)n(genc)o(y)g(response)f(entities.)31
b(Clearly)-6 b(,)24 b(this)g(is)g(also)g(not)g(lik)o(ely)h(in)e(the)h
(short)g(term.)141 3570 y(The)e(caller)i(has)e(little)i(choice)f(other)
h(than)f(to)f(trust)h(the)g(outbound)i(proxy)f(serv)o(er)f(acting)h(as)
e(an)g(ERC)f(or)h(to)g(act)h(as)f(its)0 3683 y(o)n(wn)j(ERC.)f(In)i
(the)h(former)l(,)g(more)f(lik)o(ely)h(case,)g(the)g(ERC)d(will)h
(obtain)j(the)e(ECC)e(identity)k(from)e(a)g(database)i(source)f(it)0
3796 y(trusts.)39 b(The)26 b(ERC)f(then)i(only)h(has)f(to)f(ensure)i
(that)g(the)e(call)h(reaches)i(the)e(appropriate)j(domain,)e(which)f
(standard)h(TLS)0 3909 y(serv)o(er)c(authentication)j(accomplishes,)f
(re)o(gardless)e(of)f(the)g(domain)h(name)f(used)h(by)e(the)i(ECC)c
(and)k(without)g(the)f(notion)0 4021 y(of)g(attrib)n(ute)i
(certi\002cates.)30 b(Since)23 b(a)g(caller)g(cannot)i(assume)e(that)h
(all)f(ECCs)e(will)h(ha)n(v)o(e)i(v)n(alid)f(A)l(Cs,)f(the)h(absence)i
(of)d(such)0 4134 y(a)30 b(certi\002cate)i(is)f(unlik)o(ely)h(to)f
(cause)g(the)g(caller)h(to)e(abandon)j(the)e(call)g(in)f(an)g(emer)n
(genc)o(y)-6 b(.)52 b(Thus,)32 b(the)f(transiti)n(v)o(e)h(trust)0
4247 y(model,)24 b(which)g(is)f(easier)i(to)e(implement,)i(appears)g
(to)e(be)h(a)f(more)h(pragmatic)h(approach.)0 4540 y
Fj(Normati)o(v)o(e)k(Refer)n(ences)0 4747 y Fl([1])46
b(J.)29 b(Rosenber)n(g,)k(H.)28 b(Schulzrinne,)33 b(G.)27
b(Camarillo,)32 b(A.)27 b(R.)h(Johnston,)33 b(J.)c(Peterson,)i(R.)d
(Sparks,)j(M.)d(Handle)o(y)-6 b(,)32 b(and)151 4860 y(E.)22
b(Schooler)l(,)j(\223SIP:)e(session)j(initiation)g(protocol,)-6
b(\224)25 b(RFC)d(3261,)i(Internet)h(Engineering)h(T)-7
b(ask)24 b(F)o(orce,)f(June)h(2002.)0 5047 y([2])46 b(S.)23
b(Bradner)l(,)j(\223K)n(e)o(y)e(w)o(ords)g(for)h(use)g(in)f(rfcs)h(to)f
(indicate)i(requirement)h(le)n(v)o(els,)-6 b(\224)25
b(RFC)d(2119,)j(Internet)i(Engineering)151 5160 y(T)-7
b(ask)24 b(F)o(orce,)f(Mar)-5 b(.)23 b(1997.)0 5348 y([3])46
b(A.)23 b(V)-10 b(aha-Sipila,)24 b(\223Urls)g(for)g(telephone)i(calls,)
-6 b(\224)24 b(RFC)d(2806,)k(Internet)g(Engineering)h(T)-7
b(ask)23 b(F)o(orce,)g(Apr)-5 b(.)23 b(2000.)0 5656 y
Fk(H.)18 b(Schulzrinne)1239 b Fl(Expires)25 b(June)f(2003)1240
b([P)o(age)23 b(8])p eop
%%Page: 9 9
9 8 bop 0 100 a Fl(INTERNET)-8 b(-DRAFT)640 b(draft-schulzrinne-)q(sip)
q(pin)q(g-)q(sos)q(-04)q(.ps)629 b(January)25 b(8,)e(2003)0
399 y([4])46 b(H.)17 b(Schulzrinne)k(and)e(A.)e(V)-10
b(aha-Sipila,)20 b(\223The)e(tel)h(URI)e(for)h(telephone)j(calls,)-6
b(\224)20 b(internet)g(draft,)g(Internet)h(Engineering)151
511 y(T)-7 b(ask)24 b(F)o(orce,)f(Dec.)g(2002.)34 b(W)-7
b(ork)23 b(in)h(progress.)0 699 y([5])46 b(J.)30 b(Rosenber)n(g,)j(H.)c
(F)-7 b(.)28 b(Salama,)j(and)g(M.)d(Squire,)k(\223T)-6
b(elephon)o(y)32 b(routing)g(o)o(v)o(er)e(IP)f(\(TRIP\),)-6
b(\224)28 b(RFC)g(3219,)k(Internet)151 812 y(Engineering)27
b(T)-7 b(ask)23 b(F)o(orce,)g(Jan.)g(2002.)0 1000 y([6])46
b(H.)22 b(Schulzrinne,)k(\223Dynamic)e(host)f(con\002guration)k
(protocol)e(\(dhcp-for)n(-ipv4\))j(option)d(for)e(session)i(initiation)
h(pro-)151 1112 y(tocol)f(\(SIP\))e(serv)o(ers,)-6 b(\224)24
b(RFC)e(3361,)i(Internet)h(Engineering)i(T)-7 b(ask)23
b(F)o(orce,)g(Aug.)g(2002.)0 1300 y([7])46 b(W)-8 b(.)34
b(Zhao)h(and)g(H.)f(Schulzrinne,)40 b(\223Locating)c(ip-to-public)j
(switched)d(telephone)i(netw)o(ork)e(\(PSTN\))d(telephon)o(y)151
1413 y(gate)n(w)o(ays)25 b(via)f(SLP,)-6 b(\224)21 b(internet)k(draft,)
f(Internet)i(Engineering)g(T)-7 b(ask)23 b(F)o(orce,)g(Aug.)g(2002.)34
b(W)-7 b(ork)24 b(in)f(progress.)0 1706 y Fj(Inf)m(ormati)o(v)o(e)28
b(Refer)n(ences)45 1913 y Fl([8])47 b(B.)25 b(Campbell,)j(J.)e
(Rosenber)n(g,)j(and)e(H.)e(Schulzrinne,)30 b(eds.,)d(\223Session)h
(initiation)h(protocol)g(\(SIP\))c(e)o(xtension)k(for)197
2025 y(instant)c(messaging,)-6 b(\224)25 b(RFC)d(3428,)i(Internet)i
(Engineering)g(T)-7 b(ask)23 b(F)o(orce,)g(Dec.)g(2002.)45
2213 y([9])47 b(R.)32 b(E.)g(Droms,)j(\223Dynamic)g(host)f
(con\002guration)j(protocol,)-6 b(\224)38 b(RFC)31 b(2131,)37
b(Internet)e(Engineering)h(T)-7 b(ask)34 b(F)o(orce,)197
2326 y(Mar)-5 b(.)23 b(1997.)0 2514 y([10])47 b(J.)23
b(Polk)h Fa(et)g(al.)p Fl(,)f(\223DHCP)f(option)k(for)e(geographic)j
(location,)-6 b(\224)26 b(internet)g(draft,)f(Internet)g(Engineering)i
(T)-7 b(ask)24 b(F)o(orce,)197 2626 y(Oct.)f(2002.)34
b(W)-7 b(ork)23 b(in)h(progress.)0 2814 y([11])47 b(H.)19
b(Schulzrinne,)24 b(\223DHCP)18 b(option)23 b(for)e(ci)n(vil)g
(location,)-6 b(\224)23 b(internet)g(draft,)f(Internet)g(Engineering)i
(T)-7 b(ask)20 b(F)o(orce,)h(Dec.)197 2927 y(2002.)34
b(W)-7 b(ork)24 b(in)f(progress.)0 3115 y([12])47 b(M.)22
b(P)o(atrick,)i(\223DHCP)d(relay)k(agent)g(information)h(option,)-6
b(\224)24 b(RFC)e(3046,)i(Internet)i(Engineering)g(T)-7
b(ask)23 b(F)o(orce,)g(Jan.)197 3227 y(2001.)0 3415 y([13])47
b(J.)20 b(Polk)i Fa(et)f(al.)p Fl(,)g(\223Semantics)h(for)g(DHC)d
(location)k(object)g(within)f(GEOPRIV)-12 b(,)-6 b(\224)18
b(internet)23 b(draft,)f(Internet)h(Engineer)n(-)197
3528 y(ing)h(T)-7 b(ask)23 b(F)o(orce,)g(Oct.)g(2002.)34
b(W)-7 b(ork)24 b(in)f(progress.)0 3716 y([14])47 b(M.)32
b(Garcia,)k(E.)31 b(Henrikson,)38 b(and)33 b(D.)f(L.)g(Mills,)j
(\223Pri)n(v)n(ate)f(e)o(xtensions)i(\(p-header\))g(e)o(xtensions)g(to)
d(the)g(session)197 3828 y(initiation)38 b(protocol)f(\(SIP\))e(for)g
(the)g(3rd-generation)40 b(partnership)f(project)d(\(3GPP\),)-6
b(\224)34 b(internet)k(draft,)g(Internet)197 3941 y(Engineering)26
b(T)-7 b(ask)23 b(F)o(orce,)g(No)o(v)-6 b(.)23 b(2002.)34
b(W)-7 b(ork)24 b(in)f(progress.)0 4129 y([15])47 b(D.)23
b(H.)g(Crock)o(er)l(,)j(\223Mailbox)g(names)e(for)h(common)g(services,)
h(roles)f(and)g(functions,)-6 b(\224)27 b(RFC)22 b(2142,)k(Internet)g
(Engi-)197 4242 y(neering)f(T)-7 b(ask)23 b(F)o(orce,)h(May)f(1997.)0
4429 y([16])47 b(P)-10 b(.)22 b(Resnick,)i(ed.,)f(\223Internet)j
(message)f(format,)-6 b(\224)24 b(RFC)d(2822,)j(Internet)i(Engineering)
g(T)-7 b(ask)23 b(F)o(orce,)g(Apr)-5 b(.)23 b(2001.)0
4617 y([17])47 b(S.)22 b(F)o(arrell)h(and)g(R.)f(Housle)o(y)-6
b(,)24 b(\223)-7 b(An)23 b(Internet)i(attrib)n(ute)g(certi\002cate)g
(pro\002le)f(for)f(authorization,)-6 b(\224)27 b(RFC)21
b(3281,)j(Inter)n(-)197 4730 y(net)g(Engineering)i(T)-7
b(ask)23 b(F)o(orce,)g(Apr)-5 b(.)23 b(2002.)0 5023 y
Fj(13)119 b(Change)31 b(History)0 5233 y Fi(13.1)99 b(Changes)25
b(since)g(-03)136 5407 y Fd(\017)46 b Fl(Added)24 b(description)j(of)d
(local)g(disco)o(v)o(ery)h(mechanism)g(for)f(\002nding)g(a)f(local)i
(gate)n(w)o(ay)-6 b(.)0 5656 y Fk(H.)18 b(Schulzrinne)1239
b Fl(Expires)25 b(June)f(2003)1240 b([P)o(age)23 b(9])p
eop
%%Page: 10 10
10 9 bop 0 100 a Fl(INTERNET)-8 b(-DRAFT)640 b(draft-schulzrinne-)q
(sip)q(pin)q(g-)q(sos)q(-04)q(.ps)629 b(January)25 b(8,)e(2003)136
399 y Fd(\017)46 b Fl(Noted)24 b(that)g(')-5 b(sos')25
b(is)e(case-insensiti)n(v)o(e)28 b(and)c(only)g(applies)h(to)f(SIP)e
(URIs,)g(not)i(other)h(URIs.)136 586 y Fd(\017)46 b Fl(Described)26
b(the)d(ECC)f(v)o(eri\002cation)j(options)h(a)n(v)n(ailable)g(to)d(a)g
(caller)-5 b(.)136 774 y Fd(\017)46 b Fl(Added)24 b(local)h(gate)n(w)o
(ay)f(disco)o(v)o(ery)-6 b(.)136 961 y Fd(\017)46 b Fl(Added)24
b(outline)i(of)d(ho)n(w)g(to)h(use)f(DHCP)f(for)h(con\002guring)j
(additional)h(local)d(emer)n(genc)o(y)i(numbers.)136
1149 y Fd(\017)46 b Fl(Added)24 b(3GPP)e(emer)n(genc)o(y)k(numbers)f
(be)o(yond)g(112)f(and)g(911.)0 1442 y Fj(14)119 b(Ackno)o(wledgements)
0 1649 y Fl(Andre)n(w)22 b(Allen,)g(K)n(eith)h(Drage,)f(Mik)o(e)h
(Pierce,)f(James)h(Polk,)f(Brian)h(Rosen)f(and)h(John)g(Schnizlein)i
(contrib)n(uted)g(helpful)0 1762 y(comments.)0 2054 y
Fj(15)119 b(A)-6 b(uthors')30 b(Addr)n(esses)0 2261 y
Fl(Henning)25 b(Schulzrinne)0 2374 y(Dept.)k(of)23 b(Computer)h
(Science)0 2487 y(Columbia)g(Uni)n(v)o(ersity)0 2600
y(1214)h(Amsterdam)e(A)-7 b(v)o(enue)0 2713 y(Ne)n(w)22
b(Y)-10 b(ork,)23 b(NY)f(10027)0 2826 y(USA)0 2939 y(electronic)k
(mail:)j Fh(schulzr)q(inne@cs)o(.columbia.edu)0 3188
y Fi(Full)c(Copyright)g(Statement)0 3362 y Fl(Cop)o(yright)h(\(c\))d
(The)g(Internet)j(Society)e(\(2003\).)30 b(All)23 b(Rights)i(Reserv)o
(ed.)141 3475 y(This)j(document)j(and)d(translations)k(of)c(it)h(may)f
(be)g(copied)i(and)f(furnished)i(to)d(others,)j(and)e(deri)n(v)n(ati)n
(v)o(e)h(w)o(orks)f(that)0 3588 y(comment)d(on)f(or)g(otherwise)i(e)o
(xplain)g(it)e(or)g(assist)h(in)g(its)f(implementation)j(may)d(be)g
(prepared,)j(copied,)f(published)h(and)0 3701 y(distrib)n(uted,)e(in)c
(whole)g(or)h(in)f(part,)h(without)g(restriction)i(of)d(an)o(y)h(kind,)
g(pro)o(vided)h(that)f(the)f(abo)o(v)o(e)h(cop)o(yright)i(notice)f(and)
0 3814 y(this)h(paragraph)h(are)f(included)h(on)e(all)g(such)h(copies)h
(and)e(deri)n(v)n(ati)n(v)o(e)i(w)o(orks.)31 b(Ho)n(we)n(v)o(er)l(,)23
b(this)i(document)h(itself)f(may)f(not)0 3927 y(be)29
b(modi\002ed)f(in)h(an)o(y)f(w)o(ay)-6 b(,)30 b(such)f(as)f(by)h(remo)o
(ving)h(the)f(cop)o(yright)i(notice)f(or)e(references)j(to)e(the)f
(Internet)j(Society)e(or)0 4040 y(other)21 b(Internet)i(or)n
(ganizations,)h(e)o(xcept)e(as)e(needed)i(for)f(the)g(purpose)h(of)e
(de)n(v)o(eloping)j(Internet)g(standards)f(in)f(which)g(case)0
4152 y(the)26 b(procedures)k(for)c(cop)o(yrights)j(de\002ned)e(in)f
(the)h(Internet)h(Standards)g(process)g(must)e(be)g(follo)n(wed,)i(or)e
(as)g(required)i(to)0 4265 y(translate)e(it)d(into)h(languages)i(other)
f(than)f(English.)141 4378 y(The)h(limited)h(permissions)i(granted)g
(abo)o(v)o(e)d(are)h(perpetual)i(and)e(will)f(not)h(be)f(re)n(v)n(ok)o
(ed)i(by)f(the)g(Internet)h(Society)f(or)0 4491 y(its)e(successors)i
(or)e(assigns.)141 4604 y(This)34 b(document)i(and)f(the)f(information)
j(contained)f(herein)g(is)e(pro)o(vided)i(on)e(an)h(\224AS)d(IS\224)i
(basis)h(and)g(THE)d(IN-)0 4717 y(TERNET)d(SOCIETY)g(AND)h(THE)g
(INTERNET)f(ENGINEERING)g(T)-8 b(ASK)29 b(FORCE)g(DISCLAIMS)g(ALL)i(W)
-11 b(AR-)0 4830 y(RANTIES,)23 b(EXPRESS)g(OR)i(IMPLIED,)e(INCLUDING)h
(B)o(UT)g(NO)l(T)h(LIMITED)f(T)n(O)h(ANY)g(W)-11 b(ARRANTY)23
b(THA)-10 b(T)0 4943 y(THE)18 b(USE)g(OF)g(THE)g(INFORMA)-10
b(TION)16 b(HEREIN)h(WILL)h(NO)l(T)h(INFRINGE)e(ANY)h(RIGHTS)f(OR)h
(ANY)g(IMPLIED)0 5056 y(W)-11 b(ARRANTIES)20 b(OF)i(MERCHANT)-8
b(ABILITY)18 b(OR)k(FITNESS)e(FOR)h(A)i(P)-8 b(AR)j(TICULAR)18
b(PURPOSE.)0 5656 y Fk(H.)g(Schulzrinne)1217 b Fl(Expires)24
b(June)g(2003)1217 b([P)o(age)24 b(10])p eop
%%Trailer
end
userdict /end-hook known{end-hook}if
%%EOF