CCNP - Why Frame-Relay?

Author

Why Frame-Relay?

wirelessboy

2003-04-29, 1:07 pm

hello guys

i have a basic question, why should i go for frame-relay rather than normal wan links using ppp etc.

say i have 5 offices, and all are connected through one place, how does FR have an advantage. Now without FR, all my routes come to one place and i switch them according to my needs, why FR then, i heard its fast, what else then?

in our lab scenarios we have used one 2610 as a FR switch, does anyone practically use a cisco router as a FR switch, or does everyone uses a proper one like Nortel FR switch etc.

what are the widely used FR switches?

i have not done any practical FR stuff, maybe thats why i am asking a basic doubt.

thanks in advance

peterd

2003-04-30, 2:36 am

Hello,

it's down to cost I suppose. We had Kilostream links at 64k or 128K between each of our sites, all installed and maintained by me.

Across eight sites we had 11 or 12 wan links and on our main site we had four 2503's (as it grew I could only add new 2503's
...executive decision... rather than change the first one for something that could handle multiple links!).

Now we have one link from each site into the 'cloud' so there's only one router on each site. Instead of a WAN link from here to the furthest office costing us 8000 pounds (Sterling) a year every link to the carriers backbone costs us 2500 (Sterling) a year. And each link is now a minimum 256K for the smaller offices with 2 megs from each of the larger offices.

So there are savings on the number of routers (or the size of the main router) and on the charges for the number of, and the length of, the WAN links.

Plus, in our case, BT took over the management of the WAN and my company saved my salary by making me redundant...

but they had to get me back when they found out about all of the other things that I do around here!

Regards
Peter

Yankee

2003-05-01, 2:46 pm

Maybe things are different in India (I doubt it), but in the states the frame switch is owned and maintained by the carrier of your choice. The local LEC provides service to your DEMARC point or extended DEMARC if necessary. The DEMARC point will have the LEC's NIU and the extended DEMARC if necessary will have a wall mounted jack for your T1 cable. The customer (you) is responsible for the T1 cable, CSU/DSU and the DTE device (router).

Not sure what you consider normal WAN links but I gather you mean point to point circuits. I'm not involved in pricing but it is my understanding that point to points are cheaper when available but are restricted to a limited area covered by the LEC.

As we are an internationally connected company the bulk of our circuits are frame-relay, but the regional offices near either of our two hubs frequently use point to points.

The oter thing to remember is that each point to point will take a serial port on the hub, where frame-relay can have a number of subinterfaces on that same physical hub interface.

Hope that helps,

Yankee

SureshHomepage

2003-05-02, 8:34 pm

Guys,
think of the situation, an organisation which has got 8 remote sites and 1 central head office site.

Assuming you want to have star topology ie., connecting all routers to every other router.

Think about the hardware needed at each remote site as you would need a Router with 8 Serial interfaces plus atleast 1 Comms link to each site.

If you got Frame Relay, all you need at each site is one single router with one single Serial interface connected to the FR cloud provided by your service provider.

Once FR is estabilished all you need is to buy a PVC from the provider to connect individual sites.

Eg., Central site would have a 2 Meg bearer pipe to Service Provider. And one PVC each to remote sites. You create logical interfaces for each site attaching these PVC.

Remote sites would need a single PVC to connect to Central site.

Now you reached the required star connection at a lower cost.

Also the service providers do not use the cisco routers turned into FR switches. This si good for lab purposes. In reality they use Cisco Stratacom MGX & BPX 8200 series switches. These are high end FR ATM switches to provide FR cloud also known as Edge Concentrators. Cisco acquired these products and the company who invented it called stratacom years ago. Remember the Cisco's content switching technology is from the company called arrowpoint. There is a big story how cisco acquired PIX, 1600 rotuers, 800 series, cat 5000 sereis ...etc.

Sometime ago cisco used to have the MGX and BPX exams in the old CCNP curriculam under the title WAN Switchinig, heard that they got removed or replaced couple of years ago.

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