One document matched: draft-otani-ccamp-interas-gmpls-te-01.txt

Differences from draft-otani-ccamp-interas-gmpls-te-00.txt


               IETF Internet Draft                                            T. Otani 
               Proposed status: Informational                            KDDI R&D Labs 
               Expires: May 2005                                             K. Kumaki 
                                                                                  KDDI 
                                                                            S. Okamoto 
                                                                                   NTT 
                                                                             Oct. 2004 
                
                
                           GMPLS Inter-domain Traffic Engineering Requirements 
                
                           Document: draft-otani-ccamp-interas-GMPLS-TE-01.txt 
                   
                   
                   
               Status of this Memo 
                
                  By submitting this Internet-Draft, I certify that any applicable 
                  patent or other IPR claims of which I am aware have been disclosed, 
                  or will be disclosed, and any of which I become aware will be 
                  disclosed, in accordance with RFC 3668.  "This document is an 
                  Internet-Draft and is in full conformance with all provisions of 
                  Section 10 of RFC2026. 
                   
                  Internet-Drafts are working documents of the Internet Engineering 
                  Task Force (IETF), its areas, and its working groups.  Note that      
                  other groups may also distribute working documents as Internet-Drafts. 
                   
                  Internet-Drafts are draft documents valid for a maximum of six months 
                  and may be updated, replaced, or obsoleted by other documents at any 
                  time.  It is inappropriate to use Internet-Drafts as reference 
                  material or to cite them other than as "work in progress." 
                   
                  The list of current Internet-Drafts can be accessed at 
                       http://www.ietf.org/ietf/1id-abstracts.txt 
                  The list of Internet-Draft Shadow Directories can be accessed at 
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               Abstract 
                   
                  This draft provides requirements for the support of generalized 
                  multi-protocol label switching (GMPLS) inter-domain traffic 
                  engineering (TE). Its main objective is to present the differences 
                  between MPLS inter-domain TE and GMPLS inter-domain TE.  This draft 
                  covers not only GMPLS Inter-domain architecture but also functional 
                  requirements in terms of GMPLS signaling and routing in order to 
                  specify these in a GMPLS Inter-domain environment. 
                
                
               Table of Contents 
                   
                  Status of this Memo................................................1 
                  Abstract...........................................................1 
                    
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                  1. Introduction....................................................3 
                  2. Conventions used in this document...............................3 
                  3. Assumed network model...........................................3 
                  4. Requirement of exchanging TE information across AS boundaries...6 
                  5. Requirement for GMPLS Inter-AS TE signaling, routing and 
                  management.........................................................9 
                  6. Security consideration.........................................13 
                  7. Acknowledgement................................................13 
                  8. Intellectual property considerations...........................13 
                  9. Informative references.........................................13 
                  Author's Addresses................................................14 
                  Document expiration...............................................15 
                  Copyright statement...............................................15 
                    
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               1. Introduction 
                   
                  Initial efforts of MPLS/GMPLS traffic engineering mechanism were 
                  focused on solving the problem within an Autonomous System (AS). 
                  Service Providers have come up with requirements for extending TE 
                  mechanisms across the domains (ASes as well as areas) [Inter-domain]. 
                  It discusses requirements for inter-domain Traffic Engineering 
                  mechanism with focus on packet MPLS networks and GMPLS packet switch 
                  capable (hereinafter MPLS). This document complements [Inter-domain] 
                  by providing some consideration for non-packet switch capable GMPLS 
                  networks (hereinafter GMPLS) scalability and operational efficiency 
                  in such a networking environment. 
                   
                  TE information exchanged over domains for signaling and routing GMPLS 
                  Label Switched Paths (LSPs) is more stringent than that of MPLS LSPs 
                  [MPLS-AS] from the point of an effective operation. This is because 
                  in order to dynamically or statically establish GMPLS LSPs, the 
                  additional TE information, e.g., interface switching capability, link 
                  encoding, protection, and so forth must be considered. Operators may 
                  usually use different switching capable nodes and TE links with 
                  different encoding type and bandwidth, decided by their business 
                  strategy and such TE information exchange is expected to improve 
                  operational efficiency in GMPLS-controlled networks. 
                   
                  In terms of signaling, GMPLS signaling must operate over multiple 
                  domains using exchanged TE information or a statistically configured 
                  AS route. This signaling request should take into account bi-
                  directionality, switching capability, encoding type, SRLG, and 
                  protection attributes of the TE links spanned by the path, as well as 
                  LSP encoding type and switching type for the end points. Furthermore, 
                  GMPLS LSP nesting may be applicable at the GMPLS domain borders and 
                  should be considered accordingly. 
                   
                  This document provides the requirements for the support of GMPLS 
                  inter-domain TE, investigates the necessity of dynamic or static TE 
                  information exchange between GMPLS-controlled domains and describes 
                  the TE link parameters for this routing operation.  This document 
                  also outlines GMPLS Inter-domain architecture, and provides 
                  functional requirements in terms of GMPLS signaling and routing in 
                  order to specify these in a GMPLS Inter-domain environment. 
                   
                   
               2. Conventions used in this document 
                   
                  The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 
                  "SHOULD", "SHOULD NOT", "RECOMMENDED",  "MAY", and "OPTIONAL" in this 
                  document are to be interpreted as described in RFC-2119 [RFC2119]. 
                   
                   
               3. Assumed network model 
                   
                  3.1 GMPLS Inter-AS network model 
                   
                    
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                  Figure 1 depicts a typical network, consisting of several GMPLS ASes, 
                  assumed in this document. AS1, AS2, AS3 and AS4 have multiple GMPLS 
                  inter-AS connections, and AS5 has only one GMPLS inter-AS connection. 
                  These ASes are an example of domains used without losing generality, 
                  and may be replaced by words such as others defined in [inter-domain]. 
                   
                   
                                    +---------+ 
                          +---------|GMPLS AS2|----------+ 
                          |         +----+----+          | 
                     +----+----+         |          +----+----+   +---------+ 
                     |GMPLS AS1|         |          |GMPLS AS4|---|GMPLS AS5| 
                     +----+----+         |          +----+----+   +---------+ 
                          |         +----+----+          | 
                          +---------|GMPLS AS3|----------+ 
                                    +---------+ 
                   
                                  Figure 1: GMPLS Inter-AS network model 
                   
                  Each AS is configured using various switching and link technologies 
                  defined in [Arch] and an end-to-end route needs to respect TE link 
                  attributes like multiplexing type, encoding type, etc., making the 
                  problem a bit different from the case of classical (packet) MPLS. In 
                  order to route from one GMPLS AS to another GMPLS AS appropriately, 
                  each AS needs to advertise additional TE information, while 
                  concealing its internal topology information. In addition, a 
                  signaling mechanism is required to specify a route consisting of 
                  multiple ASes, while respecting the end-pointÆs encoding, switching 
                  and payload type. Section 4 describes the TE link attributes that 
                  need to be exchanged across the AS boundary in detail. 
                   
                   
                  3.2 Comparison between a GMPLS inter-AS and a MPLS inter-AS  
                   
                  (1) GMPLS network model 
                   
                  To investigate the difference between a GMPLS inter-AS and an MPLS 
                  inter-AS network, we assume the network model shown in Fig. 2. 
                  Without loss of generality, this network model consists of two GMPLS 
                  ASes. The GMPLS AS border routers (A3, A4, B1, B2) are connected via 
                  traffic engineering (TE) links (A3-B1 and A4-B2). These inter-AS TE 
                  links are assumed to have a certain amount of bandwidth (bw), e.g., 
                  2.5Gbit/s, 10Gbit/s, etc. Moreover, each nodes in both AS 1 and AS 2 
                  can support x and y switching capabilities (e.g., x or y means TDM, 
                  Lambda or fiber). The edge node of the network (possibly A1, A2, B3, 
                  and B4) may also have the switching capability of packet (PSC1-4). 
                  Moreover, each TE link has a z or w encoding type (z or w means 
                  SONET/SDH, Lambda, Ethernet, etc.). 
                   
                   
                                                   | 
                  +-------+   z-enc. +-------+   z-enc.  +-------+   z-enc. +-------+ 
                  |A1,x-SC|----//----|A3,x-SC|-----------|B1,y-SC|----//----|B3,y-SC| 
                  +-------+   bw-1   +-------+    bw-1   +-------+   bw-1   +-------+ 
                    
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                      |                  |         |         |                  |     
                      =bw-1              =bw-1     |         =bw-1              =bw-1 
                      |z-enc.            |z-enc.   |         |z-enc.            |z-enc. 
                      |                  |         |         |                  | 
                  +-------+   w-enc. +-------+   w-enc.  +-------+   w-enc. +-------+ 
                  |A2,x-SC|----//----|A4,x-SC|-----------|B2,y-SC|----//----|B4,y-SC| 
                  +-------+   bw-2   +-------+    bw-2   +-------+   bw-2   +-------+ 
                                                   | 
                          GMPLS AS 1               |            GMPLS AS 2 
                   
                   
                                Figure 2: GMPLS Inter-AS network model (1) 
                   
                   
                  Between GMPLS AS border nodes, the routing information is statically 
                  or dynamically exchanged. Link management protocol (LMP) [LMP] may be 
                  applied to maintain and manage TE links between GMPLS AS border nodes. 
                   
                  In general, the attributes of two TE-Links (A1-B3 and A4-B2) between 
                  AS border nodes as well as switching capability of each border node 
                  shall not be always same. Therefore, GMPLS nodes shall need to 
                  identify the attributes of these TE-Links and border nodes in order 
                  to create LSP over multiple ASes. At present, GMPLS/ MPLS technology 
                  does not provide the functionality to discriminate such attributes. 
                  Furthermore, these GMPLS specific requirements for inter-area/ AS 
                  traffic engineering are not described in [Inter-domain]. 
                   
                  (2) MPLS network model 
                   
                  In the packet MPLS network, we can assume the MPLS Inter-AS network 
                  model as shown in Figure 3. There are no routing constraints such as 
                  switching capability and encoding type, compared to the GMPLS Inter-
                  AS network model. All nodes have the same switching capability of 
                  packet. 
                   
                                                   | 
                         +----+          +----+    |    +----+          +----+ 
                         | A1 |----//----| A3 |---------| B1 |----//----| B3 | 
                         +----+   2.5G   +----+   2.5G  +----+   2.5G   +----+ 
                            |               |      |        |               |     
                            =2.5G           =2.5G  |        =2.5G           =2.5G 
                            |               |      |        |               |   
                         +----+          +----+    |    +----+          +----+ 
                         | A2 |----//----| A4 |---------| B2 |----//----| B4 | 
                         +----+   10G    +----+   10G   +----+   10G    +----+ 
                                                   | 
                                MPLS AS 1          |         MPLS AS 2 
                   
                   
                                  Figure 3: MPLS Inter-AS network model 
                   
                   
                  In the following section, we consider an MPLS or GMPLS path setup 
                  from an edge node in AS 1 to an edge node in AS2. 
                    
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               4. Requirement of exchanging TE information across AS boundaries 
                
                  In this section, we describe the TE attributes that needs to be 
                  exchanged across the AS boundaries for computation of GMPLS Path. 
                   
                  4.1 Interface Switching Capability 
                   
                  A constraint of bandwidth in a GMPLS controlled network is different 
                  from that in an IP/MPLS network. In Figure 3, two TE links with 
                  different values of bandwidth such as 2.5Gbit/s and 10Gbit/s are 
                  assumed. If an MPLS LSP with 2.5Gbit/s bandwidth is established from 
                  A2 to B4 in Figure 3, two sets of TE links (that is two possible 
                  paths) can be selected (A2-A4-B2-B4 and A2-A1-A3-B1-B3-B4). 
                   
                  In the case of GMPLS inter-ASes, the ingress node needs to know the 
                  switching capabilities supported in each AS, while computing a route 
                  for a GMPLS-LSP across multiple ASes. If the switching capabilities 
                  are exchanged across the AS boundaries, the ingress node can 
                  determine the appropriate next-hop AS that is capable of supporting 
                  the requesting switching capability. 
                   
                  In the example of Figure 4, we assume a switching capability as 
                  lambda and an encoding type as lambda. The bandwidth of each TE link 
                  is, for example, corresponding to the transponderÆs bit rate of each 
                  DWDM channel. In this case, both inter-AS links may be acceptable 
                  from A2 to B4 if only TE information within each AS is considered.  
                  However, a GMPLS LSP with 2.5Gbit/s bandwidth can not be established 
                  over a set of TE links (A2-A4-B2-B4) because all nodes support only 
                  LSC which can not deal with sub-rate switching, and the 10Gbit/s TE 
                  link can only support a GMPLS LSP with 10Gbit/s. The set of TE links 
                  (A2-A1-A3-B1-B3-B4) must be used instead so as to route it over the 
                  inter AS-link of A3-B1. 
                   
                  If multiple GMPLS routes exist for a given destination via different 
                  ASes, a path should be selected satisfying these routing constraints, 
                  in addition to the conventional EGP attributes.  Although an operator 
                  may want to specify the AS border node explicitly for such a 
                  destination, this TE information exchange will improve operational 
                  efficiency in GMPLS-controlled networks. Therefore, not only IGP 
                  [GMPLS-Routing] but also EGP needs to advertise some TE parameters. 
                   
                   
                                                   | 
                    +------+   2.5G   +------+   2.5G    +------+   2.5G   +------+ 
                    |A1,LSC|----//----|A3,LSC|-----------|B1,LSC|----//----|B3,LSC| 
                    +------+  Lambda  +------+  Lambda   +------+  Lambda  +------+ 
                       |                  |        |         |                 |     
                   2.5G=Lambda        2.5G=Lambda  |      10G=Lambda       2.5G=Lambda 
                       |                  |        |         |                 |   
                    +------+    10G   +------+    2.5G    +------+   10G    +------+ 
                    |A2,LSC|----//----|A4,LSC|-----------|B2,LSC|----//----|B4,LSC| 
                    +------+  Lambda  +------+  Lambda   +------+  Lambda  +------+ 
                    
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                                                   | 
                            GMPLS AS 1             |            GMPLS AS 2 
                   
                   
                                Figure 4: GMPLS Inter-AS network model (2) 
                   
                   
                  4.2 Bandwidth Policy 
                   
                  The advertisement of the bandwidth for traversing non-local ASes is 
                  strongly dependent on the operational policy in each GMPLS AS.  The 
                  resource available for different ASes may be advertised over GMPLS 
                  inter-ASes, although the actual local bandwidth is more than that for 
                  different ASes. The GMPLS Border nodes have the functionality to 
                  control the advertised resource bandwidth to reach a destination. For 
                  example, even if 4 times OC-48 bandwidth exists to a destination in 
                  one GMPLS AS, the AS may advertise only twice OC-48 bandwidth to 
                  another GMPLS AS, following the mutual policy between these two ASes.  
                  Thus, inter-AS reachability information needs to be enhanced to 
                  include bandwidth information. 
                   
                   
                  4.3 Encoding type 
                   
                  In addition of the link switching type, an end-to-end GMPLS LSP needs 
                  to have same encoding type at all intermediate hops. In this section, 
                  we discuss the need for exchanging link encoding types across the AS 
                  boundaries. 
                   
                  The example depicted in Figure 5 is considered where TE links with a 
                  different encoding type in a GMPLS Inter-AS network are assumed. In 
                  this case, differing from the case of a packet MPLS inter-AS network, 
                  a GMPLS LSP with a specific encoding type must be established to 
                  satisfy this constraint. Since physical layer technologies used to 
                  form TE links limit the signal encoding type to be transported, the 
                  ingress node should consider this by obtaining TE parameters 
                  exchanged between GMPLS-controlled inter-ASes. In this case, both 
                  inter-AS links may be acceptable for routing from A2 to B4 if only TE 
                  information within each AS is considered. The set of TE links (A2-A1-
                  A3-B1-B3-B4) must be used instead so as to route over the inter AS-
                  link of A3-B1, satisfying the constraint of the encoding type. 
                  Therefore, inter-AS reachability information needs to be enhanced to 
                  include encoding type information. 
                   
                   
                                                 | 
                  +------+          +------+     |     +------+          +------+ 
                  |A1,LSC|----//----|A3,LSC|-----------|B1,LSC|----//----|B3,LSC| 
                  +------+   SONET  +------+   SONET   +------+   SONET  +------+ 
                     |                  |        |        |                 |     
                     =SONET             =SONET   |        =lambda           =SONET 
                     |                  |        |        |                 |   
                  +------+          +------+     |     +------+          +------+ 
                  |A2,LSC|----//----|A4,LSC|-----------|B2,LSC|----//----|B4,LSC| 
                    
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                  +------+  lambda  +------+   SONET   +------+  lambda  +------+ 
                                                 | 
                          GMPLS AS 1             |            GMPLS AS 2 
                   
                   
                                Figure 5: GMPLS Inter-AS network model (3) 
                   
                   
                  4.4 Hybrid case 
                   
                  In Figure 6, we consider a mixed case of 4.1, 4.2 and 4.3, and assume 
                  two ASes: AS 1 consisting of GMPLS nodes with TDM-SC and TE links 
                  with SONET/SDH encoding type, and AS 2 consisting of GMPLS nodes with 
                  LSC and TE links with lambda encoding type. GMPLS nodes in AS 2 
                  support sub-rate switching, for example, of 2.5Gbit/s. 
                   
                   
                                                   | 
                    +------+   2.5G   +------+    2.5G   +------+    2.5G  +------+ 
                    |A1,TSC|----//----|A3,TSC|-----------|B1,LSC|----//----|B3,LSC| 
                    +------+  SONET   +------+   SONET   +------+  Lambda  +------+ 
                       |                  |        |         |                 |     
                   2.5G=SONET         2.5G=SONET   |      10G=Lambda       2.5G=Lambda 
                       |                  |        |         |                 |   
                    +------+   10G    +------+    2.5G   +------+    10G   +------+ 
                    |A2,TSC|----//----|A4,TSC|-----------|B2,LSC|----//----|B4,LSC| 
                    +------+  SONET   +------+   SONET   +------+  Lambda  +------+ 
                                                   | 
                            GMPLS AS 1             |            GMPLS AS 2 
                   
                   
                                Figure 6: GMPLS Inter-AS network model (4) 
                   
                   
                  If a GMPLS LSP with 2.5Gbit/s is established from A2 to B4, the 
                  ingress node should know not only the reachability of B4 in AS 2 but 
                  also the switching capability of nodes in AS 2.  In this case, both 
                  inter-AS links may be acceptable for routing from A2 to B4 if only TE 
                  information within each AS is considered.  However, since the 
                  switching capability supported in each AS is different, the set of TE 
                  links (A2-A1-A3-B1-B3-B4) must be used so as to route over the inter 
                  AS-link of A3-B1. Therefore, an end-point (reachability) list 
                  consisting of node IDs, interface addresses, interface IDs per 
                  switching capability is very useful and may be advertised over GMPLS 
                  ASes. 
                   
                   
                  4.5 SRLG 
                   
                  To configure a secondary LSP in addition to a primary LSP over 
                  multiple GMPLS ASes, the parameter of Shared Risk Link Group (SRLG) 
                  is very significant. By introducing this parameter, the source node 
                  can route these LSPs so as to across the different AS border node as 
                  well as satisfy a SRLG constraint. Although this SRLG is supported 
                    
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                  and defined within an ASes, the mechanism to maintain consistency of 
                  SRLG must be considered in a GMPLS inter-domain TE environment. 
                   
                  There are cases where two different SPs may be sharing the same fate 
                  (facility) for TE links within the ASes administrated by them. 
                  However, presently there is no mechanism to allow SRLG to have global 
                  significance; SRLG administration is completely up to interconnected 
                  SPs. 
                   
                  In this document we identify that, in order to guarantee the SRLG 
                  diversity requirement, the SRLGs in an inter-domain TE environment 
                  are required to be globally unique. 
                   
                   
                  4.6 Protection Type 
                   
                  To guarantee the GMPLS LSP's resiliency over multiple GMPLS ASes, the 
                  protection type in each AS should be carefully selected so as to 
                  satisfy resilient requirement of the LSP as an end-to-end manner. 
                  This enables us to establish a LSP with a protection mechanism per 
                  AS-basis, such as link or node protection. Each GMPLS AS will provide 
                  a type of the protection to a destination within itself. Otherwise, 
                  an end-to-end recovery may be provided by calculating at the source 
                  node with the consideration of SRLG. As the same with SRLG case, 
                  protection type administration is also up to interconnected SPs. 
                  Therefore, inter-AS reachability information needs to be enhanced to 
                  include protection type information. 
                   
                   
               5. Requirement for GMPLS Inter-AS TE signaling, routing and management 
                   
                  5.1 EGP extensions for GMPLS 
                   
                  In IP/MPLS networks, the EGP such as BGP-4 is well-defined and widely 
                  deployed. However, the need for EGP extension for MPLS TE does not 
                  exist at present. Nonetheless, EGP extensions are required to support 
                  multiple GMPLS ASes as well as for layer 1 VPN [L1VPN]. GMPLS 
                  extension for multi-AS TE is required for guaranteeing inter-AS GMPLS 
                  constraints, when attempts are made to establish GMPLS LSPs over 
                  multiple domains as discussed in section 4. 
                   
                  The EGP scalability should be considered in designing GMPLS 
                  extensions to allow exchange of some TE information in addition to 
                  reachability information. Furthermore, the GMPLS EGP must be designed 
                  to achieve such operation that defects in an AS do not affect the 
                  scalability of the IGP in a different AS, although the GMPLS EGP must 
                  promptly advertise the failure within the AS, ensuring the GMPLS 
                  inter-AS connection establishment. 
                   
                  The EGP extensions for GMPLS must basically follow the GMPLS 
                  architecture [Arch], including the support of its exchange over out 
                  of band control channel. 
                   
                    
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                  The EGP must have the functionality to consider any policies for 
                  controlling TE routing information to be flooded, which will be 
                  defined between ASes on a business or operational strategy basis. 
                  This EGP routing policy should be able to be changed and configured 
                  on a per AS basis. This policy control especially in terms of 
                  switching capability may be applicable to the extensions of 
                  hierarchical routing. Each AS should control the advertisement of the 
                  switching capability or re-advertisement of received switching 
                  capability. 
                   
                   
                  5.1.1 TE parameters to be supported in EGP 
                   
                  Coinciding with MPLS Inter-AS work, the TE parameters for GMPLS 
                  Inter-AS are considered to be added. 
                   
                  A GMPLS AS border node is required to announce the following 
                  parameters in terms of node IDs, interface addresses and interface 
                  IDs, of which reachability is advertised via EGP. 
                   
                  (1) Interface switching capability 
                       (1-1)Bandwidth 
                               A. Total link bandwidth 
                               B. Max./Min. Reservable bandwidth 
                               C. Maximum LSP bandwidth  
                               D. minimum LSP Bandwidth 
                               C. Unreserved bandwidth 
                       (1-2)Switching capability:  PSC1-4, L2SC, TDM, lambda, LSC, FSC 
                  (2) Bandwidth Encoding type: As defined in [RFC3471], e.g., Ethernet, 
                  SONET/SDH, Lambda. 
                  (3) SRLG (Global view) 
                  (4) Protection type 
                   
                  As mentioned in section 4.4, an end-point (reachability) list 
                  consisting of node IDs, interface addresses, interface IDs per 
                  switching capability is formed in order to be advertised over GMPLS 
                  ASes. 
                   
                  For stitched, nested and contiguous GMPLS LSPs over multiple domains, 
                  a GMPLS LSP created within an AS will be announced as a (transit) 
                  link resource exposed to different ASes with appropriate TE 
                  parameters, while concealing intermediate nodes or interface 
                  addresses. The GMPLS EGP must support this functionality and locally 
                  configure this on the AS border nodes. 
                   
                  To ensure future interworking operation between GMPLS and MPLS, the 
                  GMPLS EGP should be also applicable to MPLS inter-AS TE (bandwidth) 
                  information exchange. 
                   
                   
                  5.1.2 EGP redistribution requirement 
                   
                  GMPLS EGP redistribution mechanisms within the domain should be 
                  provided in a scalable manner. These GMPLS EGP redistribution 
                    
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                  mechanisms must be designed to achieve such operation that a defect 
                  in an AS does not affect the scalability of IGP in a different AS, 
                  although the GMPLS EGP must promptly advertise the failure within the 
                  AS, ensuring the GMPLS inter-AS connection establishment. 
                   
                  Mechanisms for redistributing GMPLS TE information within the GMPLS 
                  domain can be a path computation element (PCE), I-BGP session, or re-
                  injection to IGP. Especially, it is useful to adopt GMPLS end-to-end 
                  basis path calculation. PCE based requirement may be incorporated 
                  with the PCE Architecture document [PCE]. 
                   
                   
                  5.2 Requirement for GMPLS Inter-AS signaling for the support of TE 
                   
                  GMPLS Inter-AS signaling must establish GMPLS LSPs over GMPLS 
                  multiple domains with a dynamic calculation of the AS route and GMPLS 
                  AS border nodes. It also must support to explicitly specify AS routes, 
                  AS border nodes and GMPLS nodes. Moreover, specifying loose GMPLS 
                  nodes including GMPLS AS border nodes must be supported in GMPLS 
                  signaling. The AS border node received GMPLS signaling message from a 
                  source node in a different AS should support recalculation mechanisms 
                  to specify the route within its domain, such as RSVP route expansion 
                  technique, followed by GMPLS Inter-AS path computation.   
                   
                   
                  5.2.1 GMPLS per-AS basis path calculation support 
                   
                  Firstly, GMPLS per-AS basis path calculation is described. In this 
                  path calculation model, a GMPLS LSP head-end specifies GMPLS AS 
                  border nodes as loose hops to tail-end statically or dynamically 
                  [Path-comp]. The route information may be learned from the GMPLS EGP. 
                  The source node also calculates the intermediate nodes to reach the 
                  selected egress AS border node. 
                   
                  Once the GMPLS path message has traversed to the connecting AS border 
                  node in the adjacent AS, another path calculation is conducted, for 
                  example, by RSVP-TE expansion to reach its destination, otherwise to 
                  reach an egress border node transiting to another AS. This path 
                  calculation will not necessarily guarantee the AS path optimality. 
                   
                   
                  5.2.2 GMPLS end-to-end basis path calculation support 
                   
                  GMPLS end-to-end basis path calculation is indicated next. In this 
                  path calculation, the GMPLS LSP head-end specifies an AS path route 
                  (for example, AS1-AS2-AS4-AS5 in Figure 1) as well as the 
                  intermediate nodes to the egress AS border node in its belonging AS. 
                  The AS border node in an adjacent AS will determine intermediate 
                  nodes followed by the specified AS path route. This path calculation 
                  will guarantee the AS path optimality, however, not necessarily 
                  guarantee end-to-end path optimality. 
                   
                   
                  5.2.3 Fast Recovery support 
                    
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                  Fast recovery operation based on the end-to-end [e2e] and segment 
                  [SEG-RECOVERY] based approach should be supported over multiple GMPLS 
                  domains, considering inter-AS link, SRLG and node diversity. These 
                  types of operation SHOULD interoperate with GMPLS intra-AS TE fast 
                  recovery mechanism. The AS border node may respond indicating a path 
                  setup error if it does not support the protection/restoration 
                  mechanism which is requested by the signaling messages generated from 
                  the source node in the different AS. 
                   
                  Depending on the recovery mode, re-optimization or revertive 
                  operations should be supported. 
                   
                   
                  5.2.4 Policy Control 
                   
                  Depending on the policy between ASes, the AS border GMPLS nodes may 
                  reject GMPLS inter-AS signaling messages if the unapproved objects 
                  are included. 
                   
                   
                  5.3 GMPLS Inter-domain TE Management 
                   
                  5.3.1 GMPLS Inter-domain TE Fault Management 
                   
                  To maintain the control channel session as well as to provide fault 
                  isolation mechanism, link management mechanisms such as [LMP] should 
                  be applied to TE links between GMPLS AS border nodes. To validate 
                  LSPs created over multiple domains, a generic tunnel tracing protocol 
                  (GTTP) may be applied [GTTP]. 
                   
                  5.3.2 GMPLS Inter-AS TE MIB Requirements 
                   
                  GMPLS inter-AS TE Management Information Bases must be supported to 
                  manage and configure GMPLS inter-AS TE in terms of GMPLS LSPs, 
                  routing, TE links and so forth.  These MIBs should extend the 
                  existing series of MIBs [GMPLS-TEMIB] to accommodate following 
                  functionalities; 
                   
                  - To manage GMPLS LSP characteristics at the tunnel head-end as well 
                    as any other points of the TE tunnel. 
                  - To include both IPv4/v6 and AS number, or only AS number in the 
                    subobjects of GMPLS RSVP ERO. A label may be included in it.  The 
                    example of the object is as follows; 
                     
                    EXPLICIT_ROUTE class object: 
                    Address1 (loose IPv4 address prefix,label, /AS1) 
                    Address2 (loose IPv4 address prefix,label, /AS1) 
                    AS2      (AS number) 
                    Address3 (loose IPv4 address prefix,label, /AS3) 
                    Address4 (loose IPv4 address prefix,label, /AS3)-destination 
                     
                    Or 
                     
                    
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                    Address1 (loose IPv4 address prefix,label, /AS1) 
                    Address2 (loose IPv4 address prefix,label, /AS1) 
                    Address3 (loose IPv4 address prefix,label, /AS2) 
                    Address4 (loose IPv4 address prefix,label, /AS2) 
                    Address5 (loose IPv4 address prefix,label, /AS3) 
                    Address6 (loose IPv4 address prefix,label, /AS3)-destination 
                     
                  - Inclusion of recording subobjects such as interface IPv4/v6 
                    addresses, AS number, a label, a node-id and so on in the RRO of 
                    the RESV message, considering the established policies between 
                    GMPLS ASes. 
                   
                   
               6. Security consideration 
                   
                  GMPLS Inter-domain TE should be implemented under a certain security 
                  consideration such as authentication of signaling and routing on the 
                  control plane as well as a data plane itself.  Indeed, this will not 
                  change the underlying security issues. 
                   
                   
               7. Acknowledgement 
                   
                  The author would like to express the thanks to Noaki Yamanaka, Kohei 
                  Shiomoto, Wataru Imajuku, Michiaki Hayashi, Zafar Ali and Adrian 
                  Farrel for their comments. 
                   
                   
               8. Intellectual property considerations 
                   
                  The IETF takes no position regarding the validity or scope of any 
                  intellectual property or other rights that might be claimed to 
                  pertain to the implementation or use of the technology described in 
                  this document or the extent to which any license under such rights 
                  might or might not be available; neither does it represent that it 
                  has made any effort to identify any such rights. Information on the 
                  IETF's procedures with respect to rights in standards-track and 
                  standards-related documentation can be found in BCP-11. Copies of 
                  claims of rights made available for publication and any assurances of 
                  licenses to be made available, or the result of an attempt made to 
                  obtain a general license or permission for the use of such 
                  proprietary rights by implementers or users of this specification can 
                  be obtained from the IETF Secretariat. 
                   
                  The IETF invites any interested party to bring to its attention any 
                  copyrights, patents or patent applications, or other proprietary 
                  rights which may cover technology that may be required to practice 
                  this standard.  Please address the information to the IETF Executive 
                  Director. 
                   
                   
               9. Informative references 
                  [RFC2119]      Bradner, S., "Key words for use in RFCs to Indicate 
                                  Requirement Levels", BCP 14, RFC 2119, March 1997. 
                    
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                  [Inter-domain]  A. Farrel, et al, "A framework for inter-domain MPLS 
                                  traffic engineering", draft-farrel-ccamp-inter-
                                  fomain-framework-00.txt, April 2004. 
                  [MPLS-AS]      R. Zhan, et al, "MPLS Inter-AS Traffic Engineering 
                                  requirements", draft-ietf-tewg-interas-mpls-te-req-
                                  09.txt, September 2004 (work in progress). 
                  [LMP]          J. P. Lang, et al, "Link Management Protocol (LMP)", 
                                  draft-ietf-lmp-10.txtö, October 2003. 
                  [GMPLS-Routing] K. Kompella, et al, "Routing Extensions in Support of 
                                  Generalized Multi-Protocol Label Switching", draft-
                                  ietf-ccamp-gmpls-routing-09.txt, October 2003. 
                  [L1VPN]        T. Takeda, et al, "Framework for Layer 1 Virtual 
                                  Private Networks", draft-takeda-l1vpn-framework-
                                  01.txt, July 2004. 
                  [PCE]          A. Farrel,et al, "Path Computation Element (PCE) 
                                  Architecture", draft-ash-pce-architecture-00.txt, 
                                  September 2004. 
                  [Arch]         E. Mannie, et al, "Generalized Multi-Protocol Label 
                                  Switching Architecture", draft-ietf-ccamp-gmpls-
                                  architecture-07.txt, May, 2003. 
                  [Path-comp]    J. P. Vasseur, et al, "Inter-domain Traffic 
                                  Engineering LSP path computation methods", draft-
                                  vasseur-ccamp-inter-domain-path-comp-00.txt, July 
                                  2004. 
                  [GMPLS-ROUTING] K. Kompella, et al, "Routing Extensions in Support of 
                                  Generalized Multi-Protocol Label Switching", draft-
                                  ietf-ccamp-gmpls-routing-09.txt. 
                  [e2e]          J. P. Lang, et al, "RSVP-TE Extensions in support of 
                                  End-to-End GMPLS-based Recovery", draft-ietf-ccamp-
                                  gmpls-recovery-e2e-signaling-01.txt, May, 2004. 
                  [SEG-RECOVERY]  L. Berger, et al, "GMPLS Based Segment Recovery", 
                                  draft-ietf-ccamp-gmpls-segment-recovery-00.txt, March 
                                  2004. 
                  [GTTP]         R. Bonica, et al, "Generic Tunnel Tracing Protocol 
                                  (GTTP) Specification", draft-ietf-ccamp-tunproto-
                                  01.txt, Sept. 2004. 
                  [GMPLS-TEMIB]   T. Nadeau, et al, "Generalized Multi-Protocol Label 
                                  Switching Traffic Engineering Management Information 
                                  Base", draft-ietf-ccamp-gmpls-te-mib-06.txt, Oct 2004. 
                   
                   
               Author's Addresses 
                   
                  Tomohiro Otani 
                  KDDI R&D Laboratories, Inc. 
                  2-1-15 Ohara Kamifukuoka     Phone:  +81-49-278-7357 
                  Saitama, 356-8502. Japan     Email:  otani@kddilabs.jp 
                   
                  Kenji Kumaki 
                  KDDI Corporation 
                  GARDEN AIR TOWER,3-10-10,Iidabshi     Phone:  +81-3-6678-3103 
                  Chiyoda-ku,Tokyo, 102-8460. Japan     Email:  ke-kumaki@kddi.com 
                   
                  Satoru Okamoto 
                    
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                  Internet Drafts draft-otani-ccamp-interas-GMPLS-TE-00.txtOctober 2004 
                   
                  NTT Network Service System Laboratory 
                  3-9-11 Midori-cho, Musashino-shi,   Phone:  +81-422-59-4353 
                  Tokyo, 180-8585. Japan       Email:  okamoto.satoru@lab.ntt.co.jp 
                   
                
               Document expiration 
                   
                  This document will be expired in May 2005, unless it is updated. 
                   
                   
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