Frame Relay Router

Discussion in 'Cisco' started by b5com, Feb 7, 2005.

  1. b5com

    b5com Guest

    We have a 192/384 Frame Relay for our internet connection.

    When one computer is downloading a file the rest of the computers on
    the network see ping times of over 800 ms and can prevent them from
    browsing the web or downloading other files.

    The router we have is a Netopia 4622.

    Even if I put a bandwidth limit on the firewall to 20K and try to
    download a file the ping times go up to 800 to 1000 ms.

    Verizon says we are going over 384 causing dropped packets.

    I've had dial up and ISDN connections that allow multiple downloads and
    web access and the ping times never went above 100 ms.

    Can a setting on the router cause this problem or is this a line
    b5com, Feb 7, 2005
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  2. b5com

    Toby Guest

    Your service provider is stating you have gone above your PIR of 384k so I
    can only assume the site you are sending from or too has a bandwidth of more
    than 384k?

    Normally you would pay for a committed rate on a PVC of CIR (192k in your
    case) which the service provider should under normal circumstances
    guarentee. and a maximum the PIR (384k in your case) which should be set to
    the smallest bandwidth of either the local site or the remote site of the
    PVC links.

    Your service provider is stating that they are dropping packets when above
    384k (PIR) so one end of the pvc must be fed by a pipe over 384k (local or
    remote end), As they are dropping packets above PIR then there must be a lot
    of queueing during high demand times which will cause at best high delays
    and at worst dropped packets. (A SP can drop packets legitimately above CIR
    and below PIR as that is what you are paying for. It's up to you to shop
    around here, it all depends on available bandwidth in the SP network. i.e.
    what seems cheap isn't as cheap as expected, some SP's are better value than
    others and the others appear better value till you use them) As your SP is
    stating dropping above PIR this does not mean they are a bad ones as all
    SP's will drop above PIR + a small amount (burst/queueing).

    I am not exacly sure what you are restricting to 20k on your firewall but as
    a guess are you restricting individual flows o/g to 20k as when d/l the o/g
    flow would just restrict ACK's (small packets) but i/c (large data packets)
    would not be restricted and hog the bandwidth.


    Delay is due to queing in/out of your site causing delays.
    You may not be comparing like with like with your old ISDN connection.


    Toby, Feb 9, 2005
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  3. b5com

    Ben Guest

    I don't know what you're router is capable of, but to alleviate this
    problem you can use frame-relay traffic-shaping. This will 'smooth out
    the bumps' in the traffic making your provider less likely to drop
    packets (note frame relay is inherently a contended service). You router
    should also be able to adapt to BECN frames received from the provider,
    indicating you're sending traffic into a temporarily congested network,
    by throttling the source.
    Ben, Feb 9, 2005
  4. b5com

    b5com Guest

    So is this a router issue or a line problem?

    If it is a setting on the router what setting needs to be configured to
    better manage packets during high demand?
    b5com, Feb 14, 2005
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