[ILUG] SSH bandwidth usage.

[Colm MacCarthaigh]

On Wed, Mar 30, 2005 at 04:43:26PM +0100, Kieran.Tully AT acm.org wrote:
> A conscientious network user would install a sniffer to measure how much of the
> network traffic they were responsible for. Of course you'd need more than one
> to get a fully representative picture of the network usage.

sniffers arn't terribly useful for gauging how much traffic you're
generating. Interface counters are a more reliable, and far easier tool
:)

> If ever given out to you can then point out that your ssh usage is
> completely secure,
> and uses miniscule bandwidth compared to that of the CIO trading MP3s and the
> MD surfing for "dinner companions" for his next business trip.

True, one other factor though is that ssh connections tend to be
long-lived and so can utilise resources in other ways. If the company
has a NAT device for example, the connection will require some
persistant state - which uses memory. 

Depending on the quality of the NAT device, the actual recourse the
resource utilisation can be tiny, but it is there and can add to what
the network administrators have to manage. To facilitate the SSH
connections they might have to lengthen the timeout period on that state
for example - which definitely will increase the ammount of memory they
need and so on. (Or of course they can just tell you to use keepalives).

-- 
Colm MacCárthaigh                        Public Key: colm+pgp at stdlib.net