[190307] in North American Network Operators' Group
Re: IP and Optical domains?
daemon@ATHENA.MIT.EDU (Phil Bedard)
Wed Jun 22 23:40:50 2016
X-Original-To: nanog@nanog.org
Date: Wed, 22 Jun 2016 23:40:43 -0400
From: Phil Bedard <bedard.phil@gmail.com>
To: Glen Kent <glen.kent@gmail.com>,
"nanog@nanog.org" <nanog@nanog.org>
In-Reply-To: <CAPLq3UNr1R=wwYwhPpL+3EgFekotZY0P6y-Fgu4rNhgyn3Vf3A@mail.gmail.com>
Errors-To: nanog-bounces@nanog.org
We have a single IP and optical group, but that=E2=80=99s not common at most larg=
er carriers. We have a fairly complex national dark fiber backbone as well =
as complicated metro networks. You see a lot of vendors tout IP/optical int=
egration around optimization of resources, but the starting point is usually=
a carrier who provisions both L3 protection and L1 circuit protection at th=
e same time. It=E2=80=99s obvious to most that isn=E2=80=99t efficient, but there are c=
arriers out there who do that because the groups are so disjoint. I would s=
ay that does not represent the majority of carriers today however. Optical =
vendors will tout optical restoration as a means to reduce excess L3 capacit=
y and they are right, with modern CDC ROADMs and coherent optics you can pla=
n a network around optical restoration and gain a lot of cost reduction by r=
educing L3 capacity. The tradeoff is in restoration times, as the photonic =
layer can=E2=80=99t restore very fast right now, so there is a middle ground for m=
ost networks of carrying either fully protected capacity at L3 or L1, and re=
storing other capacity dynamically. Typically for a subset of traffic like =
high priority traffic. =20
I read the bulk of this thread and IPoDWDM is interesting from a collapsing=
of boxes perspective if the network is simple enough it=E2=80=99s easy to operate=
and it makes financial sense. All the major router vendors are being force=
d by content providers to integrate them into their boxes. At OFC MS annou=
nced they had been working with InPhi to develop a shorter reach (80km) tuna=
ble QSFP28. If it does not need to integrate into an optical control plane =
(like one doing optical restoration) then it=E2=80=99s a very valid solution and I=
think you=E2=80=99ll continue to see growth with it. =20
I call SDN the get out of jail free card for optical vendors because they n=
o longer have to even pretend they will interoperate via standard protocols =
like GMPLS. They expose REST APIs and people are willing to take it because=
it=E2=80=99s fairly easy to deal with. =20
Phil =20
-----Original Message-----
From: NANOG <nanog-bounces@nanog.org> on behalf of Glen Kent <glen.kent@gma=
il.com>
Date: Saturday, June 18, 2016 at 17:27
To: "nanog@nanog.org" <nanog@nanog.org>
Subject: IP and Optical domains?
HI,
I was reading the following article:
http://www.lightreading.com/optical/sedona-boasts-multilayer-network-orches=
trator/d/d-id/714616
It says that "The IP layer and optical layer are run like two separate
kingdoms," Wellingstein says. "Two separate kings manage the IP and optical
networks. There is barely any resource alignment between them. The result
of this is that the networks are heavily underutilized," or, from an
alternative perspective, "they are heavily over-provisioned."
Can somebody shed more light on what it means to say that the IP and
optical layers are run as independent kingdoms and why do ISPs need to
over-provision?
Thanks, Glen
