IBM SC30-3681-08 National-personality GTE-Telenetor DDN, Pvc low/high value, Pvc low Pvc high

Con®guring the X.25 Network Interface

±An X.25 serial line having a packet size of 128 with a window size of 7 and a bit rate of 9600 bps

±An Ethernet LAN with a packet size of 1500

In this case, you should probably set the X.25 MTU to 1500. That means that about 12 packets will be sent over the X.25 interface. (MTU / X.25 packet size = number of X.25 packets to be sent).

When using an MTU of 4096, 32 packets must be sent over the X.25 interface. (4000 /128 = 31.25). In this case, packet reassembly timeouts will probably occur if the X.25 modem speed is 9600 bps. Using an X.25 modem speed of 56 Kbps would probably solve this problem.

Notes:

1.The MTU parameter has signi®cant impact on the memory requirements and memory utilization of the device. Use an MTU value of 8192 or less for devices with less than 8M of memory.

2.The amount of memory available while the device is running limits the number of SVCs that can be established and still maintain optimal performance. For recommendations on the maximum number of SVCs see the product home page on the World Wide Web.

national-personality GTE-Telenetor DDN

Sets the 28 default parameters for either GTE-Telenet or DDN National

Personality.

Default: GTE-Telenet

pvc low/high value

De®nes the lowest to the highest Permanent Virtual Circuit channel number.

Zero indicates no PVCs. By default there are no PVCs.

pvc low 0

pvc high 0

The range is 1 to 4095. These values are setting boundaries of a given VC range. There is a maximum of 400 PVCs.

Example: set pvc low 40

Note: Values must not overlap values set for SVCs.

speed speed-setting

For internal clocking, this command speci®es the speed of the transmit and receive clock lines.

Valid values: 2400 to 2048000 bps.

For external clocking, this command does not affect the hardware but it sets the speed for some protocols, such as IPX, used to determine routing cost parameters. In these cases, set the speed to match the actual line speed. The maximum line speed that can be con®gured if using external clocking is 6 312 000 bps.

Default: 9600

Note: The X.25 software is supported only at speeds up to 256 000 bps.

330MRS V3.2 Software User's Guide