CCNA question

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Feb 13th, 2008

Thanks seniors for supporting me in learning technology. That is why I am progressing.

Question about frame-relay physical topoloty. Say if we have 2-dlci's in point-to-point topology, it means we are using two serial ports of router i.e s0 & s1 or on single interface(say s0) we define both the dlci's. AND in case of multipoint what we do, I mean with single cable(provided by telco) using different dlci's we configure single serial interface. Please correct me. Regards, Tahir

I have this problem too.
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Rick Morris Wed, 02/13/2008 - 11:55

First the DLCI is the identifier of the line.

If you are using two different DLCI's on one T-1 then you will need to make sure you use sub-interfaces on that main interface you are using.

Typically you would use the DCLI as the sub-interface to keep it all clean.

Interface Serial 0/0/0 <----main interface


Interface Serial 0/0/0.500 <----Sub-interface

frame-relay interface-dlci 500


Interface Serial 0/0/0.501

frame-relay interface-dlci 501

This allows two virtual circuits, PVC's, to ride the same T-1.

The way it works in the frame-relay cloud is the provider does a mapping to that on your end your DLCI 500, location A, can talk to the distant location on their DLCI, say 300, location B.


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