Connectivity and gateway functions

TCP/IP connectivity and gateway functions handle the physical interfaces and the routing of IP data packets called datagrams. The following communication interfaces are supported by z/OS® Communications Server:

CTC

Provides access to TCP/IP hosts by way of a channel-to-channel (CTC) connection established over a System z® ESCON channel.

LCS

Provides access to TCP/IP hosts using the following devices or features:

An IBM® 3172 Interconnect Controller, which connects to a token ring, an Ethernet, or Fiber Distributed Data Interface (FDDI) local area network
An IBM 8232
An IBM 2216 Multiaccess Connector Model 400®
An OSA-2 feature: FDDI, Ethernet/Token Ring (EN/TR), or ATM in LAN emulation mode
An OSA-Express® feature: 1000BASE-T Ethernet, Fast Ethernet, ATM in LAN emulation mode, or High Speed Token Ring (HSTR)
An OSA-Express2 feature: 1000BASE-T Ethernet

MPCIPA

Provides access to:

TCP/IP hosts that use:
- OSA-Express feature: Gigabit Ethernet (GbE), 1000BASE-T Ethernet, Fast Ethernet, HSTR, or ATM in LAN emulation mode
- OSA-Express2 feature: GbE, 10 GbE, or 1000BASE-T Ethernet
- OSA-Express3 or later feature: GbE or 10 GbE
- HiperSockets™: Uses the Internal Queued Direct I/O (iQDIO). HiperSockets provides high-speed, low-latency IP message passing between logical partitions (LPARs) within a single IBM eServer™ zSeries or later server.
The OSA-Express features support the Queued Direct I/O (QDIO) architecture. IPv6 is supported on all Ethernet features in QDIO mode.
An ensemble that uses:
- OSA-Express3 or later feature configured as CHPID type OSX
- OSA-Express3 or later feature configured as CHPID type OSM

MPCOSA

Provides access to TCP/IP hosts by way of an OSA-2 adapter configured in HPDT MPC mode for Fast Ethernet or FDDI.

MPCPTP

Provides access to TCP/IP hosts through multipath channel point-to-point (MPCPTP) links. MPCPTP supports IPv4 and IPv6 protocols. MPCPTP can be used in two ways to provide direct connectivity to other mainframe hosts running z/OS Communications Server:

By using a set of two or more System z channels
By configuring to use XCF services, if the System z hosts are part of the same sysplex

MPCPTP can also be used to provide the following connectivity options:

Direct communication between two z/OS Communications Server TCP/IP Services protocol stacks running on the same MVS™ host without requiring any network attachments
Connectivity to network attachments such as the IBM 2216 Multiaccess Controller Model 400 or the IBM RS/6000®

IBM 10 GbE RoCE Express

Enables the use of Remote Direct Memory Access (RDMA) processing by using Shared Memory Communications over RDMA (SMC-R) protocols.

The VTAM® component of z/OS Communications Server provides the I/O support for each of these communication interfaces, and requires the creation (dynamically or through definition) of Transport Resource List entries (TRLEs) to represent each interface.

TRLEs must be defined for the following communication interfaces:
- MPCOSA
- MPCIPA devices not connected to an ensemble
- MPCPTP
For information about how to define these TRLEs, see z/OS Communications Server: SNA Resource Definition Reference.
For all other communication interfaces, VTAM dynamically creates TRLEs. For information about dynamically created TRLEs for TCP/IP, see z/OS Communications Server: SNA Network Implementation Guide.