gtpc1m1c | Transmission Control Protocol/Internet Protocol |
Another link layer in the TPF system is the queued direct I/O (QDIO) link
layer, which enables communication with the OSA-Express card.
The OSA-Express card has the following configuration characteristics:
- OSA-Express cards are supported by IBM Generation 5 (G5) or later
servers. The G5 or G6 server can support a maximum of 12 OSA-Express
cards. The zSeries 900 (z900) server can support a maximum of 24
OSA-Express cards. The host (for example, TPF or OS/390) can connect to
multiple OSA-Express cards. When the server is logically partitioned
(in LPAR mode), all the host LPARs in that server can share the same
OSA-Express card.
- Each OSA-Express card supports 240 symbolic device addresses
(SDAs). Each connection between the TPF system and OSA-Express requires
three SDAs: a write control path, a read control path, and a data
path. Each connection between OS/390 and OSA-Express requires at least
three SDAs; however, more are allowed because you can define multiple
data paths. The unit addresses of the SDAs must be defined in a
specific manner; see Defining OSA-Express Cards to the Processor.
- Each OSA-Express card supports a total of 512 IP addresses for all the
hosts that share that card.
- Note:
- If the total of 512 IP addresses is exceeded, results cannot be
predicted.
- You can configure the OSA-Express card by entering the ZOSAE
command. See TPF Operations for more
information on the ZOSAE command.
- Note:
- You do not need the OSA/SF feature to configure or use the OSA-Express
card.
- Each OSA-Express card has a single port that connects to a Gigabit
Ethernet (GbE or GENET) or Fast Ethernet (FENET).
Queued direct I/O (QDIO) is the link layer protocol that is used to
communicate between the OSA-Express card and host processor (the TPF
system). QDIO enables the OSA-Express card and the TPF system to share
memory; therefore data transfer does not require channel programs or use
the I/O subsystem. IP packets are sent or received on any
I-stream.