Frame Relay setup - only one shot to get it right

Unanswered Question
Aug 31st, 2007

Hi there,

For my diploma thesis I need to measure some readings regarding VoIP traffic over a frame relay connection.

I have managed to get a local university to let me work in their cisco lab, but I will have only one day to get the job done (monday) and I will not get much support from the guys there.

I am a little familiar with switch config and of course with routing but not so much with the CISCO specific stuff.

At the lab aviable are:

routers: 2500, 2600 and 3600 and switches: 2900 and 2950.

The object of the test is to check what effects it has to insert a FR link into a connection in terms of end2end quality of VoIP traffic (MOS). (e.g. none  ), header compression,...?

What I need is just a simple frame relay connection to route my stuff over.

I will have two endpoints on the two sides and a network simulator in between inserting delay and jitter and whatever.

So please don't be mad if I ask some newbie questions, but I don't have much knowledge about CISCO config and I've only got this one shot, so I need to get it right the first time 

So please could you walk the steps through with me:

1) which of the routers should I use? (shouldn't make much of a difference, should it?)

2) use one of the serials for config and connect the other to the other router

3) Now please let's walk the config together:

Following the example in the "Configuring Frame Relay"-guide wcdfrely.pdf:

Configuration for Router 1

interface serial 0

ip address 131.108.64.2 255.255.255.0

encapsulation frame-relay

keepalive 10

frame-relay map ip 131.108.64.1 43

Configuration for Router 2

interface serial 0

ip address 131.108.64.1 255.255.255.0

encapsulation frame-relay

keepalive 10

frame-relay map ip 131.108.64.2 43

Is that all? Shouldn't I have to config an IP-Interface as well for the Ethernet-port?

Do I have to setup map-classes?

Do I have to define routes?

Or does it just act transparent?

------------

Then I could go on and play with the frame fragmentation of the non-voip-traffic (vOIP pakets are not supposed to be fragmented, but how does the router know a packet is voip?)

Router(config)# map-class frame-relay map-class-name

Router(config-map-class)# frame-relay fragment fragment_size

Or I could play with IP header compression or traffic shaping and so on.

Allright, I think that's it. If I missed anything, please notify me. Well, monday's gonna be the big day ;-)

Thanks for your help and greetings,

Jan

I have this problem too.
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umedryk Thu, 09/06/2007 - 07:39

Frame Relay and X.25 is the absence of explicit, per-virtual-circuit flow control in Frame Relay. Now that many upper-layer protocols are effectively executing their own flow control algorithms, the need for this functionality at the link layer has diminished. Frame Relay, therefore, does not include explicit flow control procedures that duplicate those in higher layers. Instead, very simple congestion notification mechanisms are provided to allow a network to inform a user device that the network resources are close to a congested state. This notification can alert higher-layer protocols that flow control may be needed

http://www.cisco.com/en/US/tech/tk713/tk237/technologies_tech_note09186a008014f8a7.shtml

Paolo Bevilacqua Thu, 09/06/2007 - 10:47

One day won't be enough if you plan a fairly complete set of testing. And if you don't have experience with the routers, you may end a lot of time just to get the routers to ping sometime. Forget about map-class and sophisticated other things. it takes days and weeks sometime to figure out these things to experts too!

However, do not use the main interface. For simplicity use only use point-to-point subinterface and the frame-release interface-dlci command.

Now I 'm not sure how you will connecte the routers, but if it is back-to-back, one of them will need encapsulation frame-relay dce.

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