Expand Configuration and Management Manual (H06.03+)

Planning a Network Design
Expand Configuration and Management Manual—529522-002
3-5
Asynchronous Transfer Mode (ATM) Networks
When you are planning your Expand-over-IP environment, you may use LNP to control
over which network interfaces (IP addresses) the Expand line-handler processes run.
See Step 1 (B): Select a Process and SUBNET for NonStop TCP/IPv6 Use on
page 8-11 for examples of working with logical network partitioning.
To determine which TCP/IP subsystem is running on your system, use the SCF
LISTDEV TCPIP command. The text after the last period (.) in the Program field on the
far right of the display is either TCPIP, which identifies the process as a conventional
NonStop TCP/IP process or TCP6SAM, which identifies the process as a NonStop
TCP/IPv6 process. NonStop TCP/IP can coexist on the system with NonStop
TCP/IPv6.
For more information about LNP and about NonStop TCP/IPv6, see the TCP/IPv6
Configuration and Management Manual and the TCP/IPv6 Migration Manual. For more
information about NonStop TCP/IP, see the TCP/IP Configuration and Management
Manual.
Asynchronous Transfer Mode (ATM) Networks
Asynchronous Transfer Mode (ATM) technology is based on the efforts of the
International Telecommunication Union Telecommunication Standardization Sector
(ITU-T) Study Group XVIII to develop Broadband Integrated Services Digital Network
(BISDN) for the high-speed transfer of voice, video, and data through public networks.
ATM is a cell-switching and multiplexing technology that combines the benefits of
circuit switching (constant transmission delay and guaranteed capacity) with those of
packet switching (flexibility and intermittent traffic). ATM is a connection-oriented
environment.
The Expand-over-ATM line-handler process uses the HP ATM subsystem to
implement Expand-over-ATM connectivity. The Expand-over-ATM line-handler process
communicates with the ATM subsystem through the shared memory of the QIO
subsystem.
The major benefits of Expand-over-ATM connections are
•
Flexibility. No modifications need to be made to Expand applications to allow them
to run over ATM networks. A NonStop server that can access an ATM 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-ATM connections. Using this feature, you can configure up to eight
parallel lines between nodes.
•
High-speed connectivity and increased throughput. The ATM subsystem supports
the ATM User-Network Interface (UNI) Specification Version 3.0 over a 155 Mbps
SONET STS-3c connection.
Note. The ITU-T carries out the functions of the former Consultative Committee for
International Telegraph and Telephone (CCITT).