Frame-relay PVC bandwidth

[JohnJiang]

some one can help me with this?
Below:

Interface Serial 0.1
band width is 64.

1,that means this PVC can not burst over more than 64k?

2,what is the Max PVC-per-DLCI-Bandwidth ?

3, Is "frame-relay map ip xxx.xxx.xxx.xxx DLCI XXX" optional command?

************************************************

interface Serial0
no ip address
encapsulation frame-relay
!
interface Serial0.1 point-to-point
ip address 10.250.101.2 255.255.255.0
ip summary-address eigrp 1 10.22.128.0 255.255.128.0
bandwidth 64
frame-relay interface-dlci 95 IETF
!
interface Serial0.2 point-to-point
ip address 10.250.106.1 255.255.255.0
ip summary-address eigrp 1 10.22.128.0 255.255.128.0
bandwidth 32
frame-relay interface-dlci 120
!
interface Serial0.3 point-to-point
ip address 10.250.110.1 255.255.255.0
bandwidth 128
frame-relay interface-dlci 176

!

 

[yizhar]

HI.

The "bandwidth" configuration command is only a label and it has NO effect on the actual bandwith.
You can try using a very low "bandwidth" value and see that the actual bandwidth is what you get from the line.

This command as far as I know is only used by the router for routing decisions - when it has several routes to the same (or default) destination, it will preffer the highest bandwidth as a criteria.

Other then that, the router administrator can use the bandwidth as a label saying this interfaces connects to a serial line which has that bandwidth.

Bye
Yizhar Hurwitz

http://come.to/yizhar

http://teachers.sivan.co.il/yizhar

 

[jeter]

Specifies bandwidth allocation as a bit rate Jeter@LasVegas.com
J.Fisher CCNA

 

[svermill]

1. The use of the 'bandwidth' command has been addressed already by others.

2. You need to look into frame relay traffic shaping on CCO or in any one of a number of Cisco books. You can specify your CIR, burst rate, etc. using traffic shaping.

3. The map statement is optional in some instances. If you use subinterfaces, you must have the map statement. The frame relay switch and the router communicate via the LMI. LMI only tells the router about the active DLCIs - it has no concept of subinterfaces. Thus, the map statment is required. If there are no subinterfaces, you can add a map statement for clarity in your config file but inverse ARP will dynamically map IPs to DLCIs.

 

[JohnJiang]

http://www.cisco.com/warp/public/103/12.html#2

I finally find out the real use of "bandwidth " Use of frame relay.

YiZhar said it right. it is only a label, nothing to do with actual bandwidth.

only for restrickting EIGRP routing update percentage of the bandwidth. nothing to do with traffic shaping and route selections.

see the cisco link.

http://www.cisco.com/warp/public/103/12.html#2

 

[svermill]

John,

The bandwidth statement is indeed used for route selection. OSPF uses it to determine cost. IGRP and EIGRP also use it in determining a composite metric.

 

[JohnJiang]

Thanks for the help svermill.

It is true "bandwidth command " regarding OSPF....etc

Thanks sgain.