IBM TURBOWAYS 622 PCI MMF ATM, Инструкция по установке и использованию

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Chapter 7. Managing the Network
This chapter provides information to assist in maintaining ATM networks.
ATM Connections
ATM networks use a virtual path identifier (VPI) and a virtual channel identifier (VCI).
VPI and VCI together identify connections in the ATM network. A VPI:VCI pair defines a
path between two nodes in an ATM network. The VPI field occupies 1 byte and the VCI
field occupies 2 bytes in the ATM cell’s 5-byte header.
For the TURBOWAYS 622 PCI MMF ATM Adapter, the value of VPI must be 0. The
value of VCI can be between 0 and 1024 decimal.
Although not required, VPI:VCI values are typically assigned symmetrically; the same
values are reserved in both directions across the link. A link is the physical medium of
transmission. For example, telephone wires or microwave beams are considered links.
A link connection includes the following:
v
Physical medium for transmission
v
Protocol
v
Associated devices
v
Programming
A link connection is both logical and physical.
You can set up more than one virtual channel (VC) on the same link, but the VPI:VCI
must be different for each connection on the link. A permanent virtual channel (PVC) is
a static connection between two end stations and the ATM network. The PVC is created
by selecting a physical path from the end station through the switches to the other end
station. VPI:VCIs are assigned to establish the connection between the two end
stations. The PVC must be configured in each end station and in all switches included
in the connection.
An ATM switch performs the following functions automatically:
v
Recognizes the source of the cell
v
Changes VPI:VCI
v
Determines the destination of the cell
v
Transmits the cell to its destination
TCP/IP over ATM
Each ATM network interface can have an assigned IP (internet protocol) address. This
assigned network interface can have VPI:VCIs associated with it. This allows a TCP/IP
host, identified by its IP address, to communicate with multiple TCP/IP hosts on the
ATM network.
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