One document matched: draft-cheng-capwap-classifications-00.txt
Internet Draft H. Cheng
S. Govindan
Document: Functionality Classifications for Panasonic Singapore Labs
Control and Provisioning of Wireless Access
Points
Expires: August 2004 February 2004
Functionality Classifications for Control and Provisioning of
Wireless Access Points (CAPWAP)
draft-cheng-capwap-classifications-00.txt
Status of this Memo
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026 [1].
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
http://www.ietf.org/shadow.html.
Abstract
This document presents a means for classifying wireless local area
network (WLAN) functionality for the Control and Provisioning of
Wireless Access Points framework. It also puts forth the advantages
of using consistent classifications in dividing functionality between
the Access Controllers and Access Points that make up a WLAN.
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 [2].
H. Cheng Expires - August 2004 [Page 1]
Internet-Draft Functionality Classifications February 2004
Table of Contents
1. Introduction...................................................3
2. WLAN Functionality Classifications.............................4
3. Need for Classifications.......................................5
4. Conclusion.....................................................6
Security Considerations...........................................7
References........................................................7
Author's Addresses................................................7
Intellectual Property.............................................7
Full Copyright Statement..........................................8
H. Cheng Expires - August 2004 [Page 2]
Internet-Draft Functionality Classifications February 2004
1. Introduction
Wireless local area networks (WLANs) have generated tremendous
interests among both consumers and the industry. Consequently,
developments in this field are fast-paced and are taken up by a
number of participants. As with any process that involves diversified
participation, developments in WLAN technologies have led to the
introduction of different types of devices, architectures and
strategies. Although these advancements are based on the standardized
IEEE 802.11 specifications, they nonetheless present a host of
incompatibility issues that ultimately affect the end market.
A particular example of such incompatibility is related to WLAN
architectures that incorporate centralized controller entities or
Access Controllers (ACs). ACs were introduced to simplify the
deployment and management of large-scale WLANs by aggregating control
of a number of Access Points (APs) at a single controller entity.
Additionally, designs for these entities include consolidating some
WLAN functionality at the ACs and leaving the remaining to the APs.
While such division of functionality among APs and ACs is widely
endorsed, the specifics in which they are accomplished vary among
manufacturers and their implementations. These differences introduce
complications for consumers and enterprises, which in turn adversely
affects WLAN adoption.
This document presents a means for classifying WLAN functions based
on operational similarities. The functionality may then be divided
between ACs and APs on the basis of the classifications.
H. Cheng Expires - August 2004 [Page 3]
Internet-Draft Functionality Classifications February 2004
2. WLAN Functionality Classifications
Table 1 illustrates means for classifying WLAN functionality.
---------------------------------------------------------------------
| Type | Type | Constituent | Justifications |
| | Description | Functions | |
---------------------------------------------------------------------
| 1 | Radio | Transmission/ | Functionality common|
| | Frequency (RF) | Reception, | to the RF interface |
| | | Coding, | are to be placed |
| | | Modulation, | together. This makes|
| | | Power control, | for easier design |
| | | Wireless interface | and operation. |
| | | monitoring, | |
| | | Beacon control | |
| | | | |
| 2 | L2 Processing | Authentication, | Functionality common|
| | | Association, | to the MAC layer are|
| | | Encryption/ | to be classified |
| | | Decryption, | together so that L2 |
| | | Bridging | PDUs are processed |
| | | | in one unit. This |
| | | | follows from the |
| | | | established ISO-OSI |
| | | | layering. |
| | | | |
| 3 | L3 Processing | QoS processing, | Functionality common|
| | | Routing, | to the IP layer are |
| | | IP processing | to be classified |
| | | | together so that |
| | | | processing of L3 |
| | | | PDUs may be |
| | | | consolidated in one |
| | | | functional unit. |
| | | | |
| 4 | Control | Policy management, | General control is |
| | | Parameter settings, | common to all APs. |
| | | Configuration, | As such, these are |
| | | QoS management | to be aggregated. |
| | | Access control | |
---------------------------------------------------------------------
Table 1
H. Cheng Expires - August 2004 [Page 4]
Internet-Draft Functionality Classifications February 2004
The functionality types are classified based on their relations to
the ISO-OSI protocol layers. Functionality type 1, Radio Frequency
(RF), relates to those functional aspects that are common to the RF
interface between an AP and a mobile client. This is the physical
layer. Next, L2 processing relates to the subsequent MAC layer while
type 3 L3 processing deals with the network layer. Finally, type 4
functionality combines control aspects that are common to all APs.
The advantage of such classifications is that it is based on well
established concepts of protocol layering. This ensures that the
execution of different types of functionality may be optimized in
independent and efficient ways. And with the expected growth in WLAN
load levels, optimal performance of network entities becomes a
significant priority.
It is quite obvious from the table that the Type 2 functions
corresponds to the MAC layer functions defined by the IEEE802.11.
Therefore, it would be possible that the functions to be split in
further detail. For example, the security part, e.g. 802.11i, and the
QoS control part, e.g. 802.11e, could be separate as Type 2A, Type 2B
etc. But this kind of split of the IEEE802.11 MAC function needs to
be rectified by the IEEE. The general principle is that the split
functions could operate separately.
3. Need for Classifications
The classifications of WLAN functionality represent the integral
units that may be implemented in ACs and APs as parts of their WLAN
service capabilities. As such, enterprises may choose for example,
APs comprising types 1, 2 and 4 functionalities and a corresponding
controller capable of type 3 IP processing. Alternatively, APs may be
simplified to realize only type 1 RF functionality while a
sophisticated AC realizes the other remaining types of
functionalities. This follows from the prevailing trend where ACs
aggregate some WLAN functionality leaving only the remaining for the
APs, albeit in a structured manner.
As such, standardized means of classifications allow for consistency
in addressing various types of WLAN devices and divisions. This leads
to increased flexibility in designs for ACs and APs. Such flexibility
in turn ensures that different market requirements are addressed in
efficient and focused ways. So in addition to providing various
options for dividing functionality, the classifications also promote
interoperability between different types of devices.
The classifications also form a based for identifying different types
of APs, ACs and their compatibilities. For example, APs incorporating
H. Cheng Expires - August 2004 [Page 5]
Internet-Draft Functionality Classifications February 2004
functionality types 1 and 2 would require support from a
corresponding types 3 and 4 AC or from a set of ACs of types 3 and 4.
In essence, the classifications present opportunities for
certification processes between APs and ACs.
4. Conclusion
The classifications for WLAN functionalities presented so far need to
be realized as part of the CAPWAP effort. Doing so would allow for
ease and flexibility in WLAN deployments. Also, establishing a
consistent means of classifications would ensure interoperability
between different types of APs and ACs from different manufacturers.
Additionally, it presents opportunities to optimize network entities
so as to deliver performance commensurate with WLAN needs and
expectations. There is also a need for devising appropriate policies
for dividing functionality among ACs and APs which would further
simplify the deployment of WLANs comprising different types of
devices with varying types of functionality.
These aspects would give manufacturers greater flexibility in
designing their products knowing that they would be compatible with
devices from other manufacturers. Similarly, consumers gain with the
flexibility in choosing and deploying equipment suited to their
particular needs.
H. Cheng Expires - August 2004 [Page 6]
Internet-Draft Functionality Classifications February 2004
Security Considerations
Security is an integral issue to CAPWAP. As such, the aspects put
forth in this document will base their security requirements on that
of the broader CAPWAP goals.
References
1 "The Internet Standards Process -- Revision 3", BCP 9, October
1996, <RFC 2026>
2 "Key words for use in RFCs to Indicate Requirement Levels", BCP
14, March 1997, <RFC 2119>
Author's Addresses
Hong Cheng
Panasonic Singapore Laboratories Pte Ltd
Blk 1022 Tai Seng Ave #06-3530
Tai Seng Industrial Estate
Singapore 534415
Phone: (+65) 6554 5477
Email: hcheng@psl.com.sg
Saravanan Govindan
Panasonic Singapore Laboratories Pte Ltd
Blk 1022 Tai Seng Ave #06-3530
Tai Seng Industrial Estate
Singapore 534415
Phone: (+65) 6554 5441
Email: sgovindan@psl.com.sg
Intellectual Property
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
H. Cheng Expires - August 2004 [Page 7]
Internet-Draft Functionality Classifications February 2004
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 implementors 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.
Full Copyright Statement
Copyright (C) The Internet Society (2003). All Rights Reserved.
This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any
kind, provided that the above copyright notice and this paragraph are
included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process must be
followed, or as required to translate it into languages other than
English.
The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assignees.
This document and the information contained herein is provided on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
H. Cheng Expires - August 2004 [Page 8]
Internet-Draft Functionality Classifications February 2004
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
H. Cheng Expires - August 2004 [Page 9]
| PAFTECH AB 2003-2026 | 2026-04-24 05:42:11 |