Muni fiber: L1 or L2?

Mon Feb 4 21:17:35 UTC 2013

On 13-02-04 16:04, Scott Helms wrote:

> Subscribers don't care if the hand off is at layer 1 or layer 2 so this is
> moot as well.

This is where one has to be carefull.  The wholesale scenario in Canada
leaves indepdendant ISPs having to explain to their customers that they
can't fix certain problems and that they must call the telco/cableco to
get it fixed. (in the case of a certain cable company, they can't even
call them, it has to be done by email with response of at least 48 hours).

So splitting responsabilities can be an annoyance if it becomes very
visible to the end users.

Another aspect: customers espect to be able to switch seamlessly from
one ISP to the next. But ISP-2 can't take over from ISP-1 until ISP-1
has relinquised control over the line to the end user. In a layer 1
scenario, it means ISP-1 has to physically go and deinstall their CPE
and disconnect strand from their OLT, and then ISP-2 can do the reverse
and reconnect evrything to provide services.

What happens when ISP-1 isn't interested in a quick disconnect and ISP-2
has to wait days/weeks with end use without service ?

In a layer2 service, it is a matter of reconfiguring the OLT to pass
ethernet packets to a different VLAN to a different ISP.  No physical
changes required and it can be almost tranparent to the end user who
just has to make a new DHCP request and be provisioned by ISP-2.