RESEND WITH CORRECTED ID VERSION: Protocol Action: 0-byte Support for R-mode in Link-Layer Assisted ROHC Profile to Proposed Standard

[The IESG <iesg-secretary@ietf.org>]

The IESG has approved the Internet-Draft '0-byte Support for R-mode in 
Link-Layer Assisted ROHC Profile' 
<draft-ietf-rohc-rtp-lla-r-mode-03.txt> as a Proposed Standard.

The IESG also approved publication of Lower Layer Guidelines for Robust 
RTP/UDP/IP Header Compression 
<draft-ietf-rohc-rtp-lower-layer-guidelines-03.txt> as an Informational 
RFC.

These documents are the product of the Robust Header Compression 
Working Group. The IESG contact persons are Allison Mankin and Scott 
Bradner


Technical Summary

The "0-byte Support for R-mode in Extended Link-Layer Assisted RObust 
Header Compression Profile" defines an additional mode of the profile 
defined in "A Link-Layer Assisted ROHC Profile for IP/UDP/RTP" (now in 
the RFC Editor's queue). That document specified zero-byte header 
compression in order to avoid the single octet ROHC header in certain 
older air interfaces from pushing a packet voice stream into the next 
higher fixed packet size for the radio. The former document defined 
the zero-byte operation for Unidirectional and Optimistic modes only 
(U-mode and O-mode), but Reliable Bidirectional mode (R-mode) required 
additional work. This specification completes the Link-Layer Assisted 
0-byte profile with R-mode, with the result that the majority of 
ROHC RTP packets can be sent out (on radio links with the defined 
characteristics) with a header-free packet format during normal operation. 

The "Lower Layer Guidelines for Robust RTP/UDP/IP Header Compression" 
document describes requirements that RObust Header Compression puts on 
lower layers, especially aimed at those who are engineering and deploying 
emerging radio systems such as those specified by 3GPP, 3GPP2, ETSI, etc, 
to simplify incorporation of ROHC technology, and limit the amount of 
detail about the ROHC algorithms and protocols that need to be understood 
by link layer designers or engineers. Both general guidelines and 
guidelines specific for cellular systems are provided.


Working Group Summary 

The working group supported the publication of both of these 
documents. 

Protocol Quality

These documents were reviewed for the IESG by Allison Mankin. 
As noted, the Reliable-Mode specification was held in the WG 
for extra rounds of review, and the working group and IETF 
Last Calls did not raise issues.