nanog mailing list archives

Re: EPC backhaul networks


From: Mikael Abrahamsson <swmike () swm pp se>
Date: Sun, 30 Jan 2011 19:09:15 +0100 (CET)

On Sun, 30 Jan 2011, Glen Kent wrote:

I would like to understand why there is a preference for L3 VPNs over L2 VPNs for the EPC backhaul networks? We can use both layer 2 and layer 3 VPNs for communication between the eNodeB and the MME or S-GW, so why is it that most providers prefer L3 over L2.

Becuase the lessons learnt in the last 30 years or so of networking is that large L2 domains are considered harmful. If you subnet them down in different vlans, it means for every new vlan you need to configure something on the MME/SGW.

It's just easier and safer to break it down into smaller L3 domains that you route between.

--
Mikael Abrahamsson    email: swmike () swm pp se


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