Expand Configuration and Management Manual (G06.24+)

Subsystem Description

Expand Configuration and Management Manual—523347-008

18-67

Multipacket Frame Configuration

The FRAMESIZE modifier determines the maximum Expand packet size, in bytes,

according to the following formula:

packet_size = ( FRAMESIZE - 4 ) * 2

For example, the default value for the FRAMESIZE modifier is 132, establishing a

maximum packet size of 128 words (or 256 bytes). The FRAMESIZE modifier must be

the same value for every Expand line-handler process in the network.

You select the multipacket frame feature and determine the maximum size of a

multipacket frame by specifying the PATHBLOCKBYTES modifier. A value of 0

disables the multipacket frame feature. The default is 0. The PATHBLOCKBYTES

modifier is explained in detail in Section 17, Expand Modifiers.

Multipacket Frame Considerations

Consider the following when configuring the multipacket frame feature:

•

In a multi-line path configuration, a line and its associated multipacket frame

remain selected for outbound traffic until the multipacket frame is full or the

maximum packet count (32) has been reached. Once a multipacket frame is full, it

is transmitted, and another line and its associated multipacket frame may be

selected. Partially filled multipacket frames are transmitted if the Expand line-

handler process is momentarily inactive.

•

Because the multipacket frame feature is configured on a path-by-path basis, all

lines in a multi-line path will transport multipacket frames, or none will.

•

The value specified for the L2TIMEOUT modifier should be based on the

transmission time required for the configured PATHBLOCKBYTES modifier value

rather than the configured FRAMESIZE modifier value.

Note. The multipacket frame feature does not change the requirement that all Expand line-

handler processes in the network must be configured with the same value for the FRAMESIZE

modifier.

Note. See Considerations for Paths Using the Variable Packet Size Feature and the

Multipacket Frame Feature on page 18-70 for more configuration considerations.