[nsp] cannot burst the line

Felix Lee felixlee_hk@hotmail.com
Sun, 22 Sep 2002 03:01:01 +0000


Dear all,

The case has temporary been solved.
Along the file transfer path, there are two sites connected with two frame 
relay circuits for load-balancing.  We have found the bottle-neck is on 
these two circuit.  Finally, the traffic can be burst after putting back the 
route-cache, but they are no longer in load-balancing.

Please advise if there is any better solution?

Thanks

FL


>From: "D" <dlewis500@sanbrunocable.com>
>To: "Felix Lee" <felixlee_hk@hotmail.com>,   "dave o'leary" 
><doleary@juniper.net>
>CC: <cisco-nsp@puck.nether.net>
>Subject: Re: [nsp] cannot burst the line
>Date: Fri, 13 Sep 2002 10:40:45 -0700
>
>Used to run into similar issues like this back in the day. Quite 
>frequently.
>
>A very simple way to test some of these issues is to run 2-3 concurent file
>transfers.
>
>If one transfer does 220Kb/s, do two transfers fill the pipe to 400+Kb/s?
>If it does, then you know its not the network in the middle thats limiting
>you.
>
>-D
>
>Darrel Lewis
>
>----- Original Message -----
>From: "dave o'leary" <doleary@juniper.net>
>To: "Felix Lee" <felixlee_hk@hotmail.com>
>Cc: <cisco-nsp@puck.nether.net>
>Sent: Friday, September 13, 2002 6:16 AM
>Subject: Re: [nsp] cannot burst the line
>
>
> > At 12:48 AM 9/13/2002 +0000, Felix Lee wrote:
> > >Dear all,
> > >
> > >It is a leased circuit.  It can be bursted up to 500K at day time.  But
> > >the file copying cannot only occupy half of the bandwidth.
> >
> > Without more details, it is difficult to determine what the issue might
> > be - similar to the question/discussion posted by Blaz Zupan recently.
> >
> >   - is there another link/circuit somewhere else in the end to end path
> >          that is a bottleneck that would cause either TCP or the
>application
> >          to throttle back the transfer to 220kb/s?
> >
> >   - was the TCP window of your system holding the transfer rate to a 
>lower
> >          value because of a long delay?  See here for some hints for
> >          understanding these issues (although 220 kb/s is really quite
>low,
> >          there are also some pretty poor TCP implementations still
>lingering
> >          around out there)
> >          http://www.psc.edu/networking/perf_tune.html
> >
> >   - looking at the switching devices in the path (routers, FR switches,
>ATM
> >          switches, ethernet switches) - is there some device somewhere
>that
> >          is tossing packets?  Is it configured to do so or is it seeing
>some
> >          errors in the packets and hence throwing them away?
> >
> > I hope this provides some hints but again it is difficult to diagnose
>further
> > without more information about the network topology and environment.
> >
> >                                          dave
> >
> >
> > >FL
> > >
> > >
> > >>From: Jared Mauch <jared@puck.nether.net>
> > >>To: Felix Lee <felixlee_hk@hotmail.com>
> > >>CC: cisco-nsp@puck.nether.net
> > >>Subject: Re: [nsp] cannot burst the line
> > >>Date: Thu, 12 Sep 2002 10:52:16 -0400
> > >>
> > >>         is this frame relay?
> > >>
> > >>         if so, most telcos, etc.. have a 50% CIR (Commited 
>Information
>Rate)
> > >>that allows you to burst up to 512k at times when there is capacity 
>but
> > >>they only commit to giving you 50% of the full link speed.
> > >>
> > >>         - jared
> > >>
> > >>On Thu, Sep 12, 2002 at 02:47:12PM +0000, Felix Lee wrote:
> > >> >
> > >> > Dear all,
> > >> >
> > >> > I have a 512K link, the link can be bursted to ceiling in day time.
>I
> > >> have
> > >> > scheduled a job to copy around 3GB data from one end to another 
>atthe
> > >> night
> > >> > time, and which was expected to be completed at around 13 to 14
>hours, but
> > >> > we have only got half of the volume transferred.  Monitoring by 
>MRTG,
>we
> > >> > found the utilization of the link is flat at around 220kbps during
>file
> > >> > copying.  Can someone tell me why I cannot fully utilize the
>bandwidth?
> > >> > How can I make it?
> > >> >
> > >> > Thanks in advance.
> > >> >
> > >> > FL
> > >> >
> > >> >
> > >> > _________________________________________________________________
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> > >> > _______________________________________________
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> > >>
> > >>--
> > >>Jared Mauch  | pgp key available via finger from jared@puck.nether.net
> > >>clue++;      | http://puck.nether.net/~jared/  My statements are only
>mine.
> > >
> > >
> > >
> > >
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> >
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> >




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