SIP on FTTH systems

Mark Tinka mark.tinka at
Thu Feb 6 17:06:16 UTC 2014

On Thursday, February 06, 2014 06:38:23 PM Jean-Francois 
Mezei wrote:

> When an incumbent already has PPPoE deployed for its DSL,
> putting FTTH on PPPoE makes it simpler.

And that is the practical issue I saw (and still see). A lot 
of operators just continue with it because it is maturely 
deployed in their networks, and attempting DHCP may not be 
as easy.

Would I recommend trying DHCP, hell yes!

> And PPPoE really simplifies wholesale systems.

> You do not want the incumbent/wholesaler to perform DHCP.
> This is a HUGE headache. We have that in Canada for
> cable wholesale (TPIA). The incumbent has to micromanage
> each ISPs IP blocks and carve subnets for each CMTS (for
> cable).
> For as much as everyone hates PPPoE, it makes for
> managememnt of a wholesale systems much much easier.

In one country I worked, we pressured the incumbent to offer 
us Layer 2 backhaul instead of Layer 3, for the very same 
reasons. Co-managing IP address assignments, e.t.c., was 
problematic, especially because they were not sure how large 
their network was going to grow, which presented us with 
planning challenges in how we pre-assign address space for 
each of their service PoP's.

Of course, because the regulator had done their job re: 
unbundling the fibre, they didn't care how wholesale 
services were actually provided over said fibre. And yes, 
the incumbent jumped at the chance not to offer Layer 2 
backhaul, because then they knew everything we were up to 
(to some degree of measure).

> Ideally, there would be some protocol where the CPE would
> setup a layer 2 SVC to the ISP, after which the ISP can
> provide DHCP services etc.

Some of the vendors I've worked with don't support LNS 
functionality on their current generation BNG's. Just LAC. 
In this scenario, for PPPoE-centric operators and 
wholesalers, VPLS has been used to backhaul customer 
traffic, as opposed to L2TP, and recently, some vendors are 
now able to do this over EoMPLS pw's instead.

If you have some control over the AN's that go into the 
incumben's/wholesaler's CO, you can get that Layer 2 
connection (VPLS or EoMPLS pw) between your backbone and the 
CPE, that way.

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