[135880] in North American Network Operators' Group
Re: EPC backhaul networks
daemon@ATHENA.MIT.EDU (Owen DeLong)
Sun Jan 30 14:14:55 2011
From: Owen DeLong <owen@delong.com>
In-Reply-To: <alpine.DEB.1.10.1101301905220.13151@uplift.swm.pp.se>
Date: Sun, 30 Jan 2011 11:09:38 -0800
To: Mikael Abrahamsson <swmike@swm.pp.se>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Jan 30, 2011, at 10:09 AM, Mikael Abrahamsson wrote:
> On Sun, 30 Jan 2011, Glen Kent wrote:
>=20
>> 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.
>=20
> 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.
>=20
> It's just easier and safer to break it down into smaller L3 domains =
that you route between.
>=20
It's also easier to troubleshoot when something goes boom.
Owen
