Lucent Technologies PortMaster - Manual (Page 136)

Configuring the Location Table
8-8 PortMaster Configuration Guide
Setting the Dial Group
Dial groups associate locations with specific dial-out ports. By default, all ports and
locations belong to dial group 0 (zero). You can configure locations and ports into dial
groups numbered from 0 to 99. Dial group numbers can be used to reserve ports for
dial-out to specific locations, or to differentiate among different types of modems that
are compatible with the remote location.
The dial group associated with a location works with the dial group specified for each
port. For example, you create a dial-out location called home and specify that the dial
group for home is 2. When you configure each port, you can assign the port to a dial
group. Only ports assigned to group 2 will be used to dial the location home, while other
ports will not.
To associate a location with a dial group number, use the following command:
Command> set location Locname group Group
Setting the MTU Size
The maximum transmission unit (MTU) defines the largest frame or packet that can be
sent through this port, without fragmentation. If an IP packet exceeds the specified
MTU, it is automatically fragmented. An IPX packet that exceeds the specified MTU is
automatically dropped. PPP connections can have a maximum MTU of 1500 bytes. SLIP
connections can have a maximum MTU of 1006 bytes. With PPP, the PortMaster can
negotiate smaller MTUs when requested during PPP negotiation.
The MTU is typically set to the maximum allowed for the protocol being used. However,
smaller MTU values can improve performance for interactive sessions. During PPP
negotiation, the smaller number is used. If you are using IPX, the MTU should be set to
at least 600.
To set the MTU for a location, use the following command:
Command> set location Locname mtu MTU
Configuring Compression
Compression of TCP/IP headers can increase the performance of interactive TCP sessions
over network hardwired asynchronous lines. Lucent implements Van Jacobson TCP/IP
header compression and Stac LZS data compression. Compression is on by default.