Capwap Mailing List: Proposed changes to text in sections 3, 3.1 and 3.2

[Pat Calhoun (pacalhou) (pcalhoun]

All,

During a final review before posting the latest drafts, Dorothy wanted
to make some changes to the above sections. For the most part, these are
editorial changes, but there are some changes that could be considered
technical, so I wanted to make sure no one has issues with the new text.

<text>
3.  CAPWAP Transport

   Communication between a WTP and an AC is established using the
   standard UDP client/server model.  The CAPWAP protocol supports both
   UDP and UDP-Lite [11] transport protocols.  The UDP protocol is used
   with IPv4.  When CAPWAP is used over IPv6, the UDP-Lite protocol is
   used.  This section describes how the CAPWAP protocol is carried over
   IP and UDP/UDP-Lite transport protocols.

3.1.  UDP Transport

   One of the CAPWAP protocol requirements is to allow a WTP to reside
   behind a firewall and/or Network Address Translation (NAT) device.
   Since a CAPWAP session is initiated by the WTP (client) to the well-
   known UDP port of the AC (server), the use of UDP is a logical
   choice.  The UDP checksum field in CAPWAP packets MUST be set to
   zero.

   CAPWAP protocol control packets sent from the WTP to the AC use the
   CAPWAP control channel, as defined in Section 1.4.  The CAPWAP
   control port at the AC is the well known UDP port [to be IANA
   assigned].  The CAPWAP control port at the WTP can be any port
   selected by the WTP.

   CAPWAP protocol data packets sent from the WTP to the AC use the
   CAPWAP data channel, as defined in Section 1.4.  The CAPWAP data port
   at the AC is the well known UDP port [to be IANA assigned].  The
   CAPWAP data port at the WTP can be any port selected by the WTP.

3.2.  UDP-Lite Transport

   When CAPWAP is run over IPv6, UDP-Lite is used as the transport
   protocol, reducing the checksum processing required for each packet
   (compared to UDP and IPv6).  When UDP-Lite is used, the checksum
   field MUST have a coverage of 8 RFC 3828 [11].

   UDP-Lite uses the same port assignments as UDP.
</text>

PatC