6947ch01.fm Draft Document for Review April 7, 2004 6:15 pm
12 IBM eServer zSeries 990 Technical Guide
(when operating at 1000 Mbps (1 Gbps)) features by offloading checksum processing to
OSA-Express (in QDIO mode, CHPID type OSD)) for most IPv4 packets. This support is
available with z/OS V1R5 and later as well as Linux on zSeries.

Token Ring

The OSA-Express Token Ring feature has two independent ports, each supporting
attachment to either a 4 Mbps, 16 Mbps, or 100 Mbps Token Ring Local Area Network (LAN).
The OSA-Express Token Ring feature supports autosensing as well as any of the following
settings: 4 Mbps half- or full-duplex, 16 Mbps half- or full-duplex, 100 Mbps full-duplex.

OSA-Express ATM

The OSA-Express Asynchronous Transfer Mode (ATM) features are not supported on z990.
They are not offered as a new build option and are not offered on an upgr ade from z90 0. This
satisfies the Statement of General Direction in the hardware announcement dated April 30,
2002.
If ATM connectivity is still desired, a multiprotocol switch or router with the appropriate
network interface (for example, 1000BASE-T Ethernet, Gigabit Ethernet) can be used to
provide connectivity between the z990 and an ATM network.

OSA-2 FDDI

The OSA-2 Fiber Distributed Data Interface (FDDI) feature is not supported on z990. It is not
offered as a new build option and is not offered on an upgrade from z900. This satisfies the
Statement of General Direction in the hardware announcement dated October 4, 2001.
If FDDI connectivity is still desired, a multiprotocol switch or router with the appropriate
network interface (for example, 1000BASE-T Ethernet, Gigabit Ethernet) can be used to
provide connectivity between the z990 and a FDDI LAN.

Parallel channels and converters

Parallel channels are not supported on z990. Customers who wish to use parallel-attached
devices with z990 must obtain a parallel channel converter box such as the IBM 9034, which
may be available through IBM Global Services (IGS) or obtain a third-party parallel channel
converter box such as the Optica 34600 FXBT. In both cases, these are connect ed to an
ESCON channel.
For more information about Optica offerings, contact Optica directly:
http://www.opticatech.com/
1.3.8 CryptographicCP Assist for cryptographic function
The zSeries cryptography is further advanced with the introduction of the Cryptographic
Assist Architecture implemented on every z990 PU. The z990 processor provides a set of
symmetric cryptographic functions, synchronously executed, which enormously enhance the
performance of the encrypt/decrypt function of SSL, Virtual Private Network (VPN), and data
storing applications which do not require FIPS 140-2 level 4 security. The on-processor crypto
functions run at z990 processor speed.
Note: The demand for Token Ring on mainframe continues to decline. Migration from
Token Ring to an Ethernet infrastructure is recommended as part of long term planning for
Local Area Network support.