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Frame relay

i have a good understanding of frame relay technology but i m not sure about one thing....i know the cuircuits could be SVC and PVC.......so how come we make them SVC or PVC i eman how we configure them as that???? and Why? thanks in advance

1 ACCEPTED SOLUTION

Accepted Solutions
Purple

Re: Frame relay

Hi,

In the context of configuring a router, you don't normally have a choice between the use of SVCs and PVCs - what I mean by that is that your FR provider will sell you a service as a PVC or may offer you the ability to initiate SVCs. So firstly, you need to know what your provider is offering. Having said that, there are not too many providers out there who offer FR SVC services...

Now, if what you have a PVC, I presume you already know how to configure that.. If the provider has only sold you PVCs, you cannot configure that as an SVC.

If your provider offers you SVCs, then you can configure your router to initiate SVCs by setting up a connection to the remote end and tearing it down when no longer required. You need to have Q.922 LAPF (Link Access Procedures to Frame mode bearer services) running between your router and the switch. You then configure map-lists which map IP addresses to destination E164 or x121 addresses. The E164/X121 addresses are used to determine where the SVC will terminate... The map-list is then applied to the FR interface. When the router wishes to send data to an address configured by the map-list, it will initiate an SVC to the destination address using !.933 signaling.

Here's an example:

interface serial 0

ip address 10.1.1.1 255.255.255.0

encapsulation frame-relay

map-group SVCmap

frame-relay lmi-type q933a

frame-relay svc

!

map-list SVCmap source-addr E164 11111 dest-addr E164 22222

ip 10.1.1.10 class hawaii

!

map-class frame-relay hawaii

frame-relay cir in 128000

frame-relay cir out 128000

With this config, the router will initiate an SVC to the node at E164 address 22222 when it has data to send to 10.1.1.10

Hope that helps - pls rate the post if it does.

Paresh

1 REPLY
Purple

Re: Frame relay

Hi,

In the context of configuring a router, you don't normally have a choice between the use of SVCs and PVCs - what I mean by that is that your FR provider will sell you a service as a PVC or may offer you the ability to initiate SVCs. So firstly, you need to know what your provider is offering. Having said that, there are not too many providers out there who offer FR SVC services...

Now, if what you have a PVC, I presume you already know how to configure that.. If the provider has only sold you PVCs, you cannot configure that as an SVC.

If your provider offers you SVCs, then you can configure your router to initiate SVCs by setting up a connection to the remote end and tearing it down when no longer required. You need to have Q.922 LAPF (Link Access Procedures to Frame mode bearer services) running between your router and the switch. You then configure map-lists which map IP addresses to destination E164 or x121 addresses. The E164/X121 addresses are used to determine where the SVC will terminate... The map-list is then applied to the FR interface. When the router wishes to send data to an address configured by the map-list, it will initiate an SVC to the destination address using !.933 signaling.

Here's an example:

interface serial 0

ip address 10.1.1.1 255.255.255.0

encapsulation frame-relay

map-group SVCmap

frame-relay lmi-type q933a

frame-relay svc

!

map-list SVCmap source-addr E164 11111 dest-addr E164 22222

ip 10.1.1.10 class hawaii

!

map-class frame-relay hawaii

frame-relay cir in 128000

frame-relay cir out 128000

With this config, the router will initiate an SVC to the node at E164 address 22222 when it has data to send to 10.1.1.10

Hope that helps - pls rate the post if it does.

Paresh

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