[nsp] Cisco DS3 Questions..

Fri Feb 22 17:27:16 UTC 2002

Thus spake "Gyorfy, Shawn" <sgyorfy at elinkny.com>
> Since the topic exploded, what are your opinions on encapsulation of
leased
> line DS3s.  We currently use Frame Relay for out Point to Point DS3
> connections.  Personally, I don't know why we use FR as our encapsulation,
> and so the question to all.  If you are running Cisco to Cisco, would it
be
> wise to run HDLC or PPP?  Our DS3s' here are hardly maxed out, 15% or so,
so
> I'm not complaining about the few extra bits I can squeeze out them but
> maybe that 15% can shrink to 10% with less overhead.  Opinions or examples
> of life appreciated.

As you're finding out, this is largely a religious issue.  There are no
significant differences in overhead between HDLC, PPP, and FR.  Any
performance difference can be more easily attributed to vendor
implementation than to protocol efficiency.

In practice, HDLC is the dominant encapsulation, primarily since it's
Cisco's default.  If for no other reason, you should use HDLC because almost
everyone expects you to be using it.  PPP is obviously present in non-Cisco
shops, and anywhere MLPPP or LFI is needed.  FR is only used as a p-t-p
encapsulation in certain cases that require it; almost nobody uses it
without a good reason.

S