So I've got this 2.5gig wave, what do I do with it?

Due to the vagaries of telecom pricing, I've ended up with a 2.5gig
wavelength service between two locations when what I really wanted was a
gig-e or two.

I'm really not sure if this is a "transparent" wave service or not...
the carrier is using gear from Ciena to hand it off to us and they seem
to be big on transparent waves, so maybe it is, but nobody seems to be
able to say for sure.

So, how can I best make use of this beast in my ethernet-centered world?

1- Since it doesn't cost me anything, I'm going to try to send a
gigabit LX signal and see what happens. The handoff from the carrier to
me seems to be a plain 1310 type of signal... Light goes on, light goes
off, maybe the carrier's gear doesn't care that it's not modulating
"fast enough" and I'll get lucky?

2- MRV's EM2009-GM2 card takes 2xGE and spits out a 2.5G signal
of some sort. However they won't guarantee me that it'll work when
talking to the Ciana card the carrier is using. I should probably
inquire about their return policy and go for it.
The SFPs they spec on the trunk side are the same as those for OC48,
so as long as my wave is transparent and not expecting OC48 framing I'm
thinking this would work.

3- I can buy an OC48 box and mux some GE onto it with GFP/VCAT.
Expensive and overcomplicated since I don't need anything but ethernet.

Anyone have some clue for me? I'm starting to wish we'd just jumped to
10G waves since at least there it's clear how to interop with 10gig
ethernet.

-Will Orton
will@loopfree.net

As Facebook might caution us, "it's complicated".

It's not uncommon for a 2.5G wave to be protocol-agnostic most of the
way through, and then required to pass through a SONET/SDH framer at
the end...

You've be well-served to find somebody at your carrier clued on their
transport platform, or absent that, able to read off the configuration
options their shiny OSS GUI provides. If you could shed some light on
who the carrier is, chances are they've got a customer or two on the
list able to provide some implementation specifics.

The silver lining in this all is nobody's buying 2.5G wave service,
and as such, there's a plethora of cheap hardware options on the
secondary market able to handle the requisite circuit emulation and/or
packet forwarding -- Cisco 15454/GSR/OSM, Turin, Juniper routers with
I-1OC48-SON-SMIR and P-1GE-SX-Bs -- choose your poison. (Easier
still, albeit far less fun, upgrade to a 10G {LAN,WAN}-PHY interface
for a couple pennies more. :slight_smile:

HTH,
-a

Due to the vagaries of telecom pricing, I've ended up with a 2.5gig
wavelength service between two locations when what I really wanted was a
gig-e or two.

I'm really not sure if this is a "transparent" wave service or not...
the carrier is using gear from Ciena to hand it off to us and they seem
to be big on transparent waves, so maybe it is, but nobody seems to be
able to say for sure.

OTU-1 ?

Is it coming off a ciena CN 4200 ?

OTN / G.709 ?

Go see: http://www.ciena.com/products/flexselect_otn.htm
or this one, (but the OTN/G.709 link seems to be failing for some reason)
http://www.sonet.com/EDU/edu.htm

OTU-1 can carry an intact OC-48 that is really part of someone elses network with no undesired interactions (think "tunnel").
OTU-2 carries an OC-192 the same way, and OTU-3 is for OC-768. With the right hardware, OTU-n transports random
other optical (ethernet, storage, video, etc) signals without having them on an OC-x SONET signal. And Sonet traffic can also
be muxed in and carried with all the random other stuff on the same OTU-n pipe.

They can probably cheerily hand you either an OC-48 capable connection or an OTU-1 one to match what you are getting for hardware, but ask. Their OTU-1 based service they are providing you might be an individual wave/lambda/color but more likely is on an OTU-2 or even OTU-3 on a system that potentially carries many dozens of them on the same fiber using DWDM..

The OTN/G.709 stuff is relatively new and very desirable, Ciena has is as well and some others - see if that is what they are using.

You may want to see what Ciena has to offer you to make use of it.. They can take in an OTU-n signal in what at first glance seems to be just a transponder or possible a mux-ponder card, but they are doing a complete OEO transformation and the E part, unlike some of their competition, is used effectively to let random spare ports even on other cards in the chassis be used for components being muxed up onto this particular OTU-x signal. It is quite flexible, and that could be why you are getting confusing information about what you actually have available to you.

You could get old Cerent 454 aka Cisco 15454 gear pretty cheap, but the original 15454 gig-e cards will not make you happy.
Newer cards can give you 2 full Gig-es and probably a modest amount of spare DS3 or DS1 tdm capacity on an OC-48, but then the price will be higher.

They probably want more $$s if you ask them to hand you your "OC-48" as multiple smaller pieces (eg 2 x Gig-e), and I would think you should want to do the muxing yourself., but ask, if that is easiest for you. It will help if you KNOW what their hardware is actually capable of.

So, how can I best make use of this beast in my ethernet-centered world?

1- Since it doesn't cost me anything, I'm going to try to send a
gigabit LX signal and see what happens. The handoff from the carrier to
me seems to be a plain 1310 type of signal... Light goes on, light goes
off, maybe the carrier's gear doesn't care that it's not modulating
"fast enough" and I'll get lucky?

Unlikely. They probably have to know exactly what is coming at them, though it may be easily configured to be any of several possibilities at or around the same speed (eg OTU-1 vs OC-48)

2- MRV's EM2009-GM2 card takes 2xGE and spits out a 2.5G signal
of some sort. However they won't guarantee me that it'll work when
talking to the Ciana card the carrier is using. I should probably
inquire about their return policy and go for it.

Don't play with "returns", have them DEMO it for you for a few weeks. If they won't, shop elsewhere.

MRV has all sorts of nice "bag or tricks" gadgets, but I'd first ask Ciena what small chassis they have that can play here. It will also be a "free" education into what the carrier's own capabilities probably are, and Ciena should know what equipment is in use there.

We use these types of circuits and I manage several others for clients.
Every time I turn one up I make sure I talk to an engineer and ask if they
are expecting a 2.5Gig signal and just going to use transponders to put my
1310nm signal into a DWDM color send it to the other side, and transponder
it back to 1310nm. They've always said that's exactly what they are doing.

I used Cerent 15454 (now Cisco) w/ Oc48 IR 1310 cards facing the wave, and
proper cross connect and Gig cards (carefull here) facing my gig switches.
Shoot me an off list message and I'll help you w/ the ins and outs and share
the costs we budget for such.
I haven't used MRV but they look appealing, would love to hear other folks
experience with them as I'm about to have to turn another two of these up...

We use the MRV LamdaDrivers and they work well. We use the EM2009-G2 on our own dark fiber loops and provide dual GE connectivity on a single 2.5G wavelength. Equipment is pretty barebones, but quite solid. Management module can be rebooted without loss of light on any interfaces (besides those terminated on the management module, of course). There's plenty of options for SFPs wrt distances. However, since the OP is receiving a lit signal from the carrier, I'm not entirely sure it will work in his case, as I *believe* the trunk port requires a WDM SFP, not a standard 850/1310/1550. I could certainly be wrong, though.

-evt

Sorry to respond to my own post, but I was getting the EM2009-GM2 mixed up with another module we use. We do use the EM2009-GM2, but it does not have an SFP trunk port - it's just a pair of SC connectors on the trunk side. Looks like it can be configured for a specific wavelength by the setting of some jumpers on the module, and it looks like 1310 is possible.

-evt

http://www.undone.org.uk/em2009-gm2.jpg

The modules we have use SFPs for both Access & Trunk (WDM) ports.

The only jumpers on the boards, to my recollection, are to choose between Gigabit Ethernet
or Fibre Channel line protocol on the access ports. The trunk port protocol is mrv proprietary
at two-and-a-bit Gbit/sec (2x GigE + TDM overhead).

My understanding is that they'll support any sane choice of SFP (some MRV SFPs are clearly
NOT sane choices for this card, such as the digital video coax module..)

MRV SFP modules sold as multirate or OC48 types can be used for the trunk port. We have some
of these cards running with "normal" 1310nm SFPs in the trunk ports where we only require
two Gbit services over a single fibre pair.

I can't comment on interop with other carriers' systems - we only use these on end-to-end
dark fibre.

MRV may able to advise whether or not their trunk protocol is likely to pass through
transponders (which may well try to reshape/retime) designed to transport SONET/SDH.

d.