Expand Configuration and Management Manual (H06.03+)

Planning a Network Design
Expand Configuration and Management Manual—529522-002
3-4
Internet Protocol (IP) Networks
Internet Protocol (IP) Networks
The IP suite is an important industry standard. Expand-over-IP allows NonStop
systems to be interconnected via inexpensive IP-based routers, making a separate
Expand network unnecessary.
Expand-over-IP uses a NonStop TCP/IP process to implement the TCP/IP protocol
stack. The Expand-over-IP line-handler process communicates with the NonStop
TCP/IP process through the shared memory of the QIO subsystem.
The major benefits of Expand-over-IP connections are
•
Cost-effectiveness. Expand-over-IP allows you to route Expand paths over
industry-standard IP routers. IP-based networks allow many applications to share
high-speed links.
•
Flexibility. No modifications need to be made to Expand applications to allow them
to run over IP networks. A NonStop server that can access an IP network can be
part of the Expand network.
•
Fault-tolerance. You can use the multi-line path feature to enhance the reliability of
Expand-over-IP connections. Using this feature, you can configure up to eight
parallel lines between nodes.
•
Passthrough capability. Packets sent over an IP network path can be forwarded to
another Expand line-handler process, which can be of a different line type and in a
different processor.
Expand can use NonStop TCP/IPv6 for IP version 6 communications. You can run
NonStop TCP/IP and NonStop TCP/IPv6 at the same time.
NonStop TCP/IPv6 has three operating mode: INET, INET6, and DUAL. In the INET
mode, only IP version 4 communications are supported. In DUAL mode, both IPv4 and
IPv6 communications are supported. In INET6 mode, only IPv6 communications are
supported.
One of the differences between the conventional NonStop TCP/IP subsystem and
NonStop TCP/IPv6 for Expand is that there are no matching-processor configuration
requirements for the TCP6SAM processes and the Expand line-handler processes.
Another difference is that when you select a TCP6SAM process with which to
associate your Expand process, those processes provide access to all the configured
TCP/IP SUBNET objects and their IP addresses.
NonStop TCP/IPv6, however, introduces a feature called logical network partitioning
(LNP), that, when enabled, restricts to which SUBNET objects and IP addresses the
TCP6SAM process has access, much like the conventional NonStop TCP/IP process.
Note. On NonStop K-series servers, Expand-over-IP line-handler processes are only
supported on D40 and later systems; however, data received by an Expand-over-IP
line-handler process can be forwarded to a different type of Expand line-handler process on a
non-D40 system. In addition, data received by an Expand line-handler process on a non-D40
system can be forwarded to an Expand-over-IP line-handler process.