layer 2 data link encapsulation

Unanswered Question
Feb 29th, 2008

Hi all, can anyone tell me when we go from a normal lan ethernet network, then cross over ppp, or frame relay networks, what happens to the original layer 2 ethernet frame, does it change ?

I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Jason Fraioli Fri, 02/29/2008 - 06:05

He means that it will terminate at the device that connects to a Frame Relay, ATM, etc, network.

carl_townshend Fri, 02/29/2008 - 08:20


so when the ethernet frame goes out the say serial, or ppp, atm interface etc, whay happens to it ? does the ethernet frame get encapsualted or changed ?

Jason Fraioli Fri, 02/29/2008 - 08:46

correct. With frame relay you might see PPP or HDLC encapsulations. With ATM you are going to see cells.

carl_townshend Fri, 03/07/2008 - 05:45

so what changes? does the ethernet frame get converted to ppp frame? or is the ethernet frame still exsist but encapsulated in ppp, atm etc?

please explain

Joseph W. Doherty Fri, 03/07/2008 - 16:54

The original Ethernet frame is discarded. Assuming you're doing IP, the L3 IP packet is encapsulated within the L2 frame for the media it's being sent across.


This Discussion