Changing T1 from copper to fiber

[NastyNed2]

Hi all, I haven't been here in a while. Seems the name of the forum changed from Meridian to CS1000.

I have an Option 51 and a number of Option 11 switches connected via leased point-to-point T1s from our telco. We now have a city-wide fiber system installed, and I'd like to convert the PRIs from telco copper to our own fiber. I don't want to convert them to IP packets and back again, I simply want to use fiber instead of copper (light instead of electrons). Seems to me we did it this way in a previous job, but I wasn't as directly involved.

Questions:
1) Can I do this?
2) What type of CSU should I be looking for to accomplish this?
3) Do I have to change any configuration in my PRI loops? Right now they're mostly B8ZS, but a couple are AMI.
4) Should I do it this way, or am I better off converting to IP packets and running these circuits through the network cloud, thereby not burning up fiber pairs to each of the locations?
4) Anything else I haven't asked already?

Thanks,

Ned

 

[Badphoneman]

You can do it with a fibermux, there are a number of different makes. hook the pri up just like you would to the mux like you would to a csu and the fiber on the other side. Depending on the mux you buy, there maybe some configuration on it. B8ZS and ESF this sort of thing. I've done this qutie a bite in the past, but it's been awhile. IP trunks have taken it's place.

 

[curtismo]

Questions:
1) Can I do this?
Yes
2) What type of CSU should I be looking for to accomplish this?
As the previous responder stated, yes you can with a fiber T-1 modem (or whatever the manufacture calls it). RAD and Transition Networks are a couple of products that come up if you search for "t1 fiber extender". You will want to match your fiber type (more than likely single-mode) and the distance is also important.
3) Do I have to change any configuration in my PRI loops? Right now they're mostly B8ZS, but a couple are AMI.
Probably not, although clocking may be an issue.

4) Should I do it this way, or am I better off converting to IP packets and running these circuits through the network cloud, thereby not burning up fiber pairs to each of the locations?
How many sites do you have? Is the city fiber set for a "star" or "ring" topology? Lots of questions you will need to investigate. I lease city-owned fiber for my IP network for seven sites, with voice (CS 1000 IP, Nortel IP phone and 9150) and data on the same fiber. The sites are laid out in a fashion that I had the city splice the two strands I lease in ring topology. I then have routing switches at each site and use OSPF as the routing protocol. With this I have pretty much less than a second changeover in case of failure of a link. This also provides some protection against backhoe (or in my case, tree limb or car accident) fade, and also periodic work that has to be performed on the fiber (road construction, insertions of new fiber loops, etc.) I would be looking at converting your network to IP as that is where the world is heading. If you have to rent a pair of fibers, you could also use BX optics (transmit and receive on one pair) using both pair and increase your bandwidth to 2 Mbps and further protect from failures. Or you could put data on one strand and the T1 fiber modems on the other. It all depends on what you want, how much disaster protection you want, how the phone side and the data side of your business get along, and whether you want to upgrade your systems to VoIP trunking now or later.

 

[NastyNed2]

I work for the city, and this is the city fiber I'm wanting to use to connect city PBXs, so there's no leasing of fiber involved. It's the leasing of point-to-point circuits from the telco that I want to eliminate. In a previous job (electric utility) our PBXs were connected via tie lines using both microwave and later fiber once the company installed fiber to all locations. I wasn't as directly involved in that, so I'm not sure how we connected the PBXs to the fiber or the microwave.

 

[tnphoneman]

Adtran makes equipment for just this purpose.

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http://www.greatwhitetechnologies.com

Aastra Authorized Reseller

 

[NastyNed2]

Thanks. I'll look for Adtran. Just found a RAD fiber modem a few minutes ago.

 

[curtismo]

The City that I lease my fiber from has a Nortel 81C phone system and their remote fiber cabinets on the City Light fiber. I know they also have some 9150 IP remote systems running on their fiber. Their problem is that their fiber has become popular with outside parties (schools, leasees like me, etc.) so the number of strands available to certain parts of the city is limited.

If you've got the strands, might as well use it. It appears you have an immediate view to stop getting charged by the local telco, which you can meet with the fiber T1 conversion equipment. But you also probably need to look down the road also towards where telephony is going, which is IP.

 

[NastyNed2]

We're planning to convert all of our (outdated) Option 11s to VoIP. We're looking for a more immediate ROI on our fiber, however, I'm beginning to think that the money spent on fibermuxes might be better spent on VoIP gear. Also, even though we have 144 strands now, every point to point fiber connection is inefficient use of that fiber. We also have numerous outside concerns asking us about leasing fiber, especially Chicago area interests that want to locat DR sites out in our area.

So, we do have to watch our strand budget. Thank goodness for DWDM.