PCI Token Ring Administrator's Guide

Token Ring Resources
Manual Installation and Configuration
Chapter 368
support MTU’s as low as 4540 bytes. MAUs support 18000, but
they do not support full duplex (FDX). Consult your switch
manual before configuring the MTU.
Also note that HP-PB (J2166A) and EISA (J2165A and J2638AA)
currently support an MTU of 4170 bytes. If PCI Token Ring is to
be connected to a network containing HP-PB Token Ring, it is
best to set PCI Token Ring’s MTU at 4170.
The following patches or patches that supersede them allow
MTUs of up to 4500 bytes on HP-PB and EISA Token Ring:
No patches are required for 11i.
f. In a shared ring (stations are connected by a MAU), the first
station to enter the ring should not use autosense. The
remaining stations can use autosense. If autosense is not used,
the speed should match the first station. FDX cannot be enabled
in a shared ring environment.
To configure 100 Mb/s operation, enable autosense. 100 Mb/s
operation is supported only when all of the following
requirements are met:
1. A5783A is used.
On-line diagnostics (IPR 9904 and later) may be used to
distinguish between A4930A (4/16 PCI Token Ring) and
A5783A (4/16/100 PCI Token Ring) in 11.x. Starting with
B.11.00.06, ioscan(1M) can also be used to distinguish
between the two.
2. The adapter is connected to a 100 Mb/s port.
3. Software A5783A revision B.10.20.00 or later or B.11.00.04
or later is installed.
4. Autosense is enabled.
Table 3-2 Patches Required to Increase MTU Size
10.20 11.0
HP-PB PHNE_17536 PHNE_17355
EISA Not available PHNE_17942