Frame-Relay Traffic Shaping Problem (one DLCI)

Posted on 2004-11-18
Last Modified: 2010-04-10
I have a problem that involves a hub and spoke topology network.

The central site has a 2MB connection into a BT IP Clear MPLS Based Network with Frame-Relay Encapsulation.

The Remotes are 256K/128K sites into cloud.

I need to be able to state on the Router at the central site:

"If you need to get to a 256K Remote site send at 256K. And same for 128K."

I have Frame-Relay defined but only have one DLCI in use - DLCI 101 (same at remote sites):

interface Serial0/0:0
 description Virtual Serial Port for E1 Channelized using Frame
 bandwidth 1984
 no ip address
 encapsulation frame-relay IETF
 frame-relay lmi-type ansi
interface Serial0/0:0.101 point-to-point
 description Frame Relay to BT IP Clear 2MB
 bandwidth 1984
 ip unnumbered Loopback0
 frame-relay interface-dlci 101

Do I need to use Frame-Relay Traffic Shaping? And if so how can I specfiy bandwidth on a per site scenario - with only one DLCI to get to all sites??

The problem I am facing at the moment is - BT say that the central site is sending data too fast for the remote sites to receive therefore packet loss is occuring. They say theres nothing they can do to implement a "flow-control" scenario?

Any help is greatfully received.

Question by:c1sc0m4n
    LVL 5

    Expert Comment

    Unfortunately, by using MPLS, you no longer really have a hub and spoke technology.  Each of your locations is connected to an MPLS cloud and only within the cloud do your (virtual) tunnels to each of your remote locations get built.
    Because of this, as you note, a traditional Frame Relay traffic shaping setup won't do the job.

    In effect, you've outsourced your WAN to BT via their MPLS cloud.  Although they may not provide flow control as you are used to it, they should be providing traffic shaping with Class of Service within their network.  
    They should be able to:
      - Mark packet priority as the packets enter the MPLS network so that, even when the head end is sending too much traffic, the right packets always get through.
      - Respect packet priority you set.  Even if you can't set a bandwidth level within your router, you should be able to set DSCP or TOS bits on your edge routers so that the data is properly prioritized when it hits BT.

    If someone from BT says they don't do this, ask for higher level support to explain why.

    Author Comment

    Hmm I think i've found a solution anyway. I can create class maps at the centre with policies that specifiy bandwidth based on the defined ACL. Need to test it and see.

    BT have found a fault anyhow - but I rekon i still was over cooking on bandwidth..... we'll see what we get.


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