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Frame Relay - Don't understand fully

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gmonahan

IS-IT--Management
Jul 12, 2004
4
NZ
I'm new to Frame Realy - I've just started working with a company who have Frame Relay in place - forgive me if I sound stupid but - Is Frame Relay like a leased line, can you use it to connect to a second site and also use it for internet access? Would love any infromation?
 
Well, it's like a leased line, but I don't see how a leased line allows you to connect both to a remote site and the Internet. Unless you mean that site1 has an Internet connection, and site2 has a f/r PVC (permanent virtual circuit) to site1, then yes. Site2 could access the Internet via site1.

The main benefit of frame relay is cost. You can pay for a lower fixed rate and "burst" above that rate when needed. It's also not as distance-sensitive as leased lines. I think that Frame's biggest benefit is when you have more than 2 sites to connect since each site only has a local loop (T1, fractionsl T1, DS3, whatever), and then a fairly low-cost "virtual" circuit.
 
I am not sure if anyone will see this since its an old thread but I would like to ask a question anyway.

What is the significance of the DLCI to frame-relay circuits?

 
The signigicane of the DLCI in Frame Relay is in simple terms the identifier for both ends of the connection between 2 or more circuits.

For instance you have two frame-relay circuits installed one in Florida and one in Georgia that will connect two offices together. The frame-relay cloud which is the telco does not know the two circuits belong to each other with just the Circuit ID's. They use DLCI's which are the PVC or SVC (Perminent Virtual Circuit/Switched Virtual Circuit) identifier. In this case the telco will tell the frame cloud to connect all traffic on DLCI 16 to DLCI 17. And for you in the routers you tell the 16 router to go to DLCI 17 and vice versa. A frame circuit is not the same as a point to point circuit and if I beleive correctly can be switched within the telco's network up to 15 times before getting to its destination. Hope this helped.
 

Yes, that does help. Thank you.

One more question if you dont mind? Are the DLCIs assigned by the telco, or can the administrator assign his/her own DLCIs depending on which circuits are required to communicate?
 
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