HP 3000 Manuals HP 3000 Manuals
ARPA Transport Enhancements
by Nancy DeVorei
Information Networks Division
This version of ARPA Transport includes enhancements that provide an
increased feature set, better performance, increased connectivity
capacity, and support of a Token Ring type network.
ARPA Transport has several new features:
* ARPA Transport now includes a subset of the 4.3 BSD compliant
Socket interface. This interface supports the nowait select
capability and allows access to the TCP and UDP protocols.
* Domain Name support has been added to ARPA Transport. Domain
Names are transparently resolved in addition to NS node names.
* A Default Gateway can now be configured within NMMGR. All packets
with unresolved paths are forwarded to the default gateway.
* IEEE802.3 and Probe can now be disabled.
* The MAP table entries for LAN and Token Ring are aged every 5
minutes.
* Protocols, such as TCP, can provide advice to the address
resolution module for questionable paths.
* Nettool has been updated to reflect the changes in the transport
subsystem data structures.
* SNMP now supports the TCP and UDP groups, the Token Ring link
interfaces group, and link up and link down traps.
To achieve better performance for TCP and UDP, various changes and
improvements were made. Now TCP and UDP run on the Interrupt Control
Stack (ICS) when processing inbound packets from either LAN or Token Ring
drivers. This results in less overall CPU utilization and greater line
utilization. TCP algorithms have been improved to more efficiently
handle processing of in-order packets. Probe and ARP packets are now
filtered on the ICS, only packets of interest to the system are
processed. Inbound network traffic capacity has been increased. TCP
supports 4096 connections from as many as 4096 different systems over
both Token Ring and LAN. UDP supports 512 sockets.
A Token Ring type Network is now supported with MPE/iX Release 4.0. The
NS and Host-Based ARPA Services are supported over the Token Ring link.
These services use ARP for address resolution. Token Ring is as simple
to configure as the 802.3 link. Source routing is also supported over
Token Ring.