[lug] Traceroute question

D. Stimits stimits at idcomm.com
Wed Dec 13 13:41:43 MST 2000

Michael Deck wrote:
> I have a funny thing going on with traceroute. When I ssh away from my box
> to a machine elsewhere, and then traceroute back to my box, I go through
> about 12 hops mostly in the 13msec range, and then when I get to the last
> hop it's in the 250msec range.
> But when I traceroute from my machine to the other one, it's the same 12
> hops but each one shows approximately 250msec.
> I probably don't understand the output of traceroute. Can anyone explain
> what's happening?
> -Mike
> Michael Deck
> Cleanroom Software Engineering, Inc.

Assuming it is a 56k modem, most people don't realize that in one
direction it is still a 33.6k modem. From your machine out is 33.6k,
from the outside to you is a 56k (there are other limits, like all
modems being throttled back to like 53k for telephone reg's). The ISP
does not have to do a digital/analog conversion going from them to you,
whereas coming from you to them, they must do so (the lack of
digital/analog conversion from their end to you gives it the boost). Or
something like that (somebody else probably has a better explanation
than that). One of the advantages of ISDN is that there are no
digital/analog conversions at any point, so a 56k (non-existent) ISDN
would be superior to a 56k modem (even on the best phone line).

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