Con®guring Frame Relay Interfaces

Valid Values: See ªCommitted Burst (Bc) Sizeº on page 397

Default Value: 64 000

be Sets the default value of be to the value provided by a Frame Relay network provider.

Valid Values: See ªExcess Burst (Be) Sizeº on page 397

Default Value: 0

Example:

FR 6 config> set cir-default

Default Committed Information Rate (CIR) in bps [64000]? 48000

Default Committed Burst Size (Bc) in bits [64000]? 40000

Default Excess Burst Size (Be) in bits [0]? 52000

clocking [external or internal]

 

To connect to a modem or DSU, con®gure clocking as external. To connect

directly to another DTE device, use a DCE cable and set the clocking to

internal. For internal clocking, you must enter the set line-speedcommand

to con®gure a clock speed between 2400 and 2048000 bps.If you want to

use a line speed greater than 2048000, you can only do this on:

v interface 1.

 

v port 1 of a 4-port WAN concentration adapter.

v ports 1 and 5 of an 8-port WAN concentration adapter.

The other WAN ports must be clocked at 64 Kbps or less.

For external clocking the maximum line speed is 6 312 000 bps.

encoding [NRZ or NRZI]

 

 

Sets the HDLC transmission encoding scheme as NRZ (non-return to zero)

 

or NRZI (non-return to zero inverted). Most con®gurations use NRZ, which

 

is the default.

 

frame-size #

 

 

Sets the maximum size of the network layer portion of the frames

 

transmitted and received on the interface. This maximum size includes the

 

2-byte DLCI address and the user data shown in ®gure 39-4. The size you

 

con®gure must be consistent with the maximum frame size supported by

 

the Frame Relay switch and by the other FR DTEs in the Frame Relay

 

network. Values are 262 to 8190. The default is 2048. Since the con®gured

 

frame size includes the DLCI address and the FR RFC 1490 multi-protocol

 

encapsulation header, the maximum protocol packet size that can be

 

transmitted is less than the con®gured frame size and is protocol

 

dependent. The following table shows how many bytes to subtract from the

 

con®gured frame size to determine the maximum protocol packet size that

 

can be transmitted and received on the interface.

IP

 

4 bytes

IPX

 

10 bytes

Appletalk Phase 2

10 bytes

DECnet Phase IV (DNA IV)

12 bytes

Banyan Vines

10 bytes

OSI

 

10 bytes

Bridging

 

10 bytes

Chapter 31. Con®guring and Monitoring Frame Relay Interfaces 429

Page 465
Image 465
IBM SC30-3681-08 manual Valid Values See ªCommitted Burst Bc Sizeº on, Clocking external or internal, Is the default