TOUR Transition Release Notes (September 2004)(11i v1 and 11i v2)

Transport Optional Upgrade Release Transition Release Notes
Announcement
7
HP-UX Transport Enhancements
This section provides a summary of the HP-UX transport enhancements included in
PHNE_35351.
Limited Transmit This feature was introduced in TOUR 1.0.
The transition patch PHNE_35351 (for HP-UX 11i v1) implements a TCP loss recovery
enhancement. The enhancement is transparent to users. Under certain circumstances, users
will experience performance improvement. For more information, see RFC 3042, "Enhancing
TCP's Loss Recovery Using Limited Transmit.
This RFC specifies a new Transmission Control Protocol (TCP) mechanism that can be used to
more effectively recover lost segments when the congestion window of a connection is small, or
when a large number of segments are lost in a single transmission window. The Limited
Transmit algorithm calls for sending a new data segment in response to each of the first two
duplicate acknowledgments that the sender receives. Transmitting these segments increases
the probability that TCP can recover from a single lost segment using the fast retransmit
algorithm, instead of using a costly retransmission timeout. Limited Transmit can be used
both in conjunction with, and in the absence of the TCP selective acknowledgment (SACK)
mechanism.
Multicast Listener Discovery (MLD) This feature was introduced in TOUR 1.0.
PHNE_35351
and
PHNE_35765
• NOSYNC Support
• Forward-Retransmission Timeout
(F-RTO)
• New Parameter for the route
Command
• Congestion Window Validation
• Internal TCP and UDP Enhancements
11i v1
and
11i v2
September
2004
3.0
PHNE_35765
• Dynamic keying support for MIPv6
A.02.01 (or later) with IPSec A.02.01
(or later)
11i v2
September
2004
3.0
Table 2 Transport Enhancements
Transition
Patch
Transport Enhancement
HP-UX
Version
Introduced
in TOUR