nanog mailing list archives

Re: Well done Sprint!


From: Network Operations Center <noc () nwrain net>
Date: Thu, 13 Nov 1997 18:15:56 -0800 (PST)


        Hello alex,

On Thu, 13 Nov 1997, Ex-Support Wench wrote:

What do y'all think of pathchar *as it is now*?  How reliable is it for
determining actual _available bandwidth_?  I thought according to VJ,
CAIDA, Cisco and even the NSF it was "way-alpha"? 

        From the testing I've done the results are a reasonable
        approx. of the -available- bandwitdh.  I have also seen
        some very outragious output out of the utility (solaris).
        The linux version isn't able to figure out the MTU so
        you have to specify it on the command line, when traversing
        a slower link the out put from the far side can be -very-
        un-reliable.

                        Hth,    JimL

Steve Blair wrote:

well, one could get Van Jacobson's pathchar, and learn the
true capacity that way. I could care less what *theoretical
bandwidth* is available, when customers complain. I want to
know what bandwidth *is available*, and pathchar goes a very
long way towards that end.

link labelling could be arguably silly, if you're basing your
determination on a competetitor's labels, you could 
get some unusual surprises IMHO...

-- 
steve c blair        tivoli systems inc      sblair () dev tivoli com
"Why can't we blast them onto someone else's property?"

'Vadim Antonov writes...'
**> 
**> There's no use in promoting corporate paranoia at the expense of
**> engineering cooperation.  It is like butcheing the hen which lays
**> the golden eggs.  Knowing link capacity was useful (while it lasted)
**> to get the idea of what is more likely to be dropping packets
**> on the floor when customers complained.





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