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

Transport Optional Upgrade Release Transition Release Notes

Announcement

HP-UX Transport Enhancements

This section provides a summary of the HP-UX transport enhancements included in

PHNE_35765.

NOSYNC Support This feature was introduced in TOUR 3.0.

In previous releases of the TCP/IP stack, the IP module had to serially handle multiple

requests arriving on the same queue. The NOSYNC feature, a new STREAMS

synchronization level, removes this restriction and enables the IP module to handle requests

simultaneously. The transition patch PHNE_35765 (for HP-UX 11i v2 September 2004)

improves network throughput for high speed network interfaces such as multi-port Gigabit

cards in an Auto Port Aggregation (APA) configuration or 10Gigabit cards.

Forward-Retransmission Timeout (F-RTO) This feature was introduced in TOUR 3.0.

When a retransmission timeout occurs, the last window of data is retransmitted. Spurious

retransmission timeouts occur, especially due to mobile network devices switching between

access points. In such cases, the unnecessary retransmission of the last window of data

degrades TCP performance.

The transition patch PHNE_35765 (for HP-UX 11i v2 September 2004) implements the

F-RTO algorithm supported by RFC 4138 to detect spurious timeouts.

Table 2 Transport Enhancements

Transition

Patch

Transport Enhancement

HP-UX

Version

Introduced

in TOUR

PHNE_35765

• NOSYNC Support

• Forward-Retransmission Timeout

(F-RTO)

• New Parameter for the route

Command

• Congestion Window Validation

• Internal TCP and UDP Enhancements

• Dynamic keying support for MIPv6

A.02.01 (or later) with IPSec A.02.01

(or later)

11i v1

and

11i v2

September

2004

3.0