IBM 990 OSA-Express

Chapter 1. IBM zSeries 990 overview 11

Draft Document for Review April 7, 2004 6:15 pm 6947ch01.fm

򐂰IBM TotalStorage SAN Switches 2109-F16, S16, and S08

򐂰IBM TotalStorage Director 2109-M12

FICON Cascaded Directors have the added value of ensuring high integrity connectivity.

Transmission data checking, link incidence reporting, and error checking are integral to the

FICON architecture, thus providing a true enterprise fabric.

For more information on Cascaded Directors, consult the I/O Connectivity Web page:

http://www.ibm.com/servers/eserver/zseries/connectivity/ficon_cascaded.html

OSA-Express

With the introduction of z990 and its increased processing capacity, and the availability of

multiple LCSSs, the Open Systems Adapter family of local area network (LAN) adapters is

also expanding by offering a maximum of 24 features per system (versus the maximum of 12

features per system on prior generations). The z990 can have 48 ports of LAN connectivity.

You can choose any combination of OSA features: the OSA-Express Gigabit Ethernet LX

(FC1364), the OSA-Express Gigabit Ethernet SX (FC1365), the OSA-Express 1000BASE-T

Ethernet (FC1366), or OSA-Express Token Ring (FC2367). You can also carry forward your

current z900 OSA-Express features to z990, OSA-Express Gigabit Ethernet LX (FC 2364),

OSA-Express Gigabit Ethernet SX (FC 2365), OSA-Express Fast Ethernet (FC 2366), and

OSA-Express Token Ring (FC 2367).

The OSA-Express GbE features (FC1364, and FC1365) have an LC Duplex connector type,

replacing the current SC Duplex connector. This conforms to the fiber optic connectors

currently in use for ISC-3 and the FICON Express features shipped after October 30, 2001.

The z990 supports a copper Ethernet feature: 1000BASE-T Ethernet. This feature is offered

on new builds and replaces the current OSA-Express Fast Ethernet (FC 2366), which can be

brought forward to z990 on an upgrade from z900.

1000BASE-T Ethernet is capable of operating at 10, 100, or 1000 Mbps (1 Gbps) using the

same Category-5 copper cabling infrastructure that is utilized for Fast Ethernet. The Gigabit

over copper adapter allows a migration to gigabit speeds wherever there is a copper cab ling

infrastructure instead of a fiber optic cabling infrastructure.

An additional function of the OSA-Express 1000BASE-T Ethernet feature is its support as an

OSA-Express 100BASE-T Ethernet Integrated Console Controller. This function supports

TN3270E and non-SNA DFT 3270 emulation and means that 3270 emulation for console

session connections are integrated in de z990 via a port of the 1000BASE-T Ethernet feature.

A function introduced for the Linux on zSeries and z/OS environments, called checksum

offload, provides the capability of calculating the Transmission Control Protocol/User

Datagram Protocol (TCP/UDP) and Internet Protocol (IP) header checksums.

Checksum verifies the correctness of files. By moving the checksum calculations to a Gigabit

or 1000BASE-T Ethernet feature, host CPU cycles are reduced.

Improved performance can be realized by taking advantage of the checksum offload function

of the OSA-Express Gigabit Ethernet, and OSA-Express GbE or the 1000BASE-T Ethernet