1. PPP and Frame Relay both are l2 protocols.
I know about PPP, about CHAP etc. I know a few things about FR
also..Like the packets are broken down into frames and transmitted, and
about DLCIs.. But I am not able to get the exact differences between
PPP and Frame Relay.
HDLC is used on point-to-pont serial links suc as T1s, DS3 and now
Packet-over-SONET (POS). It has a low overhead in terms of the
additional bytes required over and above the layer 3 payload. There is
no authentication protocol for HDLC.
PPP was and is heavily used in async dial-up and provide for
authentication using PAP or CHAP protocol. Now there is also PPP over
Ethernet (PPPoE).
A variation of PPP known as multi-link PPP (MLPPP) is quite popular for
loading balancing parallet circuit like T1's.
HDLC is used on point-to-pont serial links suc as T1s, DS3 and now
> Packet-over-SONET (POS). It has a low overhead in terms of the
> additional bytes required over and above the layer 3 payload. There is
> no authentication protocol for HDLC.
>
> PPP was and is heavily used in async dial-up and provide for
> authentication using PAP or CHAP protocol. Now there is also PPP over
> Ethernet (PPPoE).
PPP and Cisco HDLC has the *same* amount of overhead. PPP is the more
modern and probably better maintained protocol. PPP is also heavily used
on point-to-pont links.
Oct 20, 2010
