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Building a TCP/ IP Network Over Dark Fiber?
1101z asks: "Well I work for a public access station in a city where a second cable/phone/internet company has moved just started operating. Part of there deal with the city was to let us have (for free) dark fiber links between several location in the city and our studio, so that we would be able to cablecast live from those locations. As the computer guy I would like to be able to interconnect computer networks that already exist at several of those locations, when we are not using the fiber for cablecast. The question is what is the cheapest way to build a TCP/IP network over this dark fiber." I wonder if the fiber being used is related to this story, from a month ago?
"Dark fiber" is a nice buzzword, but has nothing to do with your question:
"I don't know how to design a network, can someone do it for me?"
Even if someone was willing to do this for you, the answer's no, since you've given absolutely no details about sites, number of users, applications.. really, anything useful to go on other than that you want to use TCP/IP.
There is no 'network in a box'; everyone's requirements are different. If you would post some of your requirements, we might be able to give you some ideas.
The key word there was "cheapest," Sparky. Cisco gear is a lot of things, but it is never, ever cheapest. Ever.
Get advice from a network consultant, because you need someone who knows what to buy and how to hook it up. With the right kind of hardware, you can probably share with the video link too (might be expensive, that's why you need some advice).
What type of pixy dust are you selling to be able to declair the above statement to be a flamebait?
It is clear from the question that he will *sometimes* have access to a fiber link. He doesn't state what network equipment he already has. He doesn't state if he wants to do load balancing with an existing connection. He doesn't state if network downtime when the fiber is not available for computer networking is acceptable. He doesn't state what type of speed he is looking to get (10, 100, Gig?). He doesn't state what he needs to be able to do with it (makes a big difference between passing email between sites or centralizing all computer backups).
Just because some Slashdot readers are willing to "consult" for free doesn't mean that we should be rewarded with ever increasingly open ended questions such that we need to discuss more possible senarios because the one issued in the question is incomplette.
I like helping people. I would be willing to guess that "duffbeer703" probably likes helping people too. But his response is approbate considering that this person clearly hasn't done enough to even figure out what a complette question is. At some point it should be made that you get more useful answers from Ask Slashdot if you ask complette specific questions.
Otherwise, if you actually believe that telling him to get a clue is a flaimbait then I suggest you also go looking for the "question" for Life, the Universe and Everything. Is there a finite number of ways to get an answer of 42? Is there a finite number of ways to light fiber for computer networking? Shall I see if the mysql database on Slashdot is on a large enough hard drive for me to count the ways....
You're new to this whole "dark fiber" thing, aren't you? When a telco sells you "dark fiber" they're either literally selling you unused MMF, with repeaters in place, or they're selling you an unused lambda. In either case, the interface to customer equipment is multi-mode fiber, and you can run anything over it that you would run over a shorter piece of fiber.
Again, you assume way too much. First of all, the poster says that the city was to let us have (for free) dark fiber links between several location in the city and our studio. He did not say a telco was providing him with anything. Further he says dark fibre links. He does not say that they are providing bandwidth or lamdas, meaning that it cannot be assumed that they have repeaters or muxes or DWDM equipment on these links. It is entirely possible, if not likely that they are getting strands of glass and nothing more.
You also talk about multi-mode fibre. While it is true that telcos often provide a multimode fibre connection to their customers, this is just a short link back to the telco's multiplexer on a single mode sonet ring. This case could easily be just glass strands, like I said before. If that is the case then they are much more likely to be single mode because multi mode cannot run the same distances that single mode can. If the run is longer than a kilometer it will almost certainly be single mode and require totally different equipment than the multimode scenario you propose. Again we don't know that from the post, as I stated earlier the poster did not provide nearly enough information to answer the question. But, maybe you are correct, provided that your other assumtion was correct when you said You're new to this whole "dark fiber" thing, aren't you?
The long answer is that if you haven't done this before you better get some consulting help. Chances are you are talking about a ring topology and are going to be linking sites with different networks.
Perhaps you have telco supplied networks for each office hooked up over DSL or T1. If that's the case, have fun getting routing working without having the telco people disconnect you. Good luck reconfiguring the telco routers for that matter.
Routing complex networks is tough. Do you already have VPN's interconnecting these sites? Are you going to be introducing redundant routes? How are you going to manage these routes? IOS can suck if you've never seen how to configure routing processes. Routing software is also complex. Ripv2 is about as simple as it gets and it doesn't offer much control over which route you take -- the only metric is hop count. OSPF has design guides as big as phone books.
If you have a bunch of nats at your different locations, do the networks overlap? Are you going to have to renumber your networks?
If you are just playing in your spare time, you won't be able to do this for under a few grand. Fibre connections are generally not cheap. If you're lucky you could put a few fibre nics into a couple of linux boxes, but I don't foresee those nics being under $400 each.
If this is to be a business network, do it right from the start or you'll make yourself look stupid. People expect the stuff they don't understand to just work. There will be very little tolerance if services are going up and down and your fibre links are to blame.
-- DrZaius - Minister of Sciences and Protector of the Faith
Hmmm...seems everyone wants to either be a smart*** or overanalyze this. First off: It appears that he is working with the local cable company, so, actually, he has already defined what sort of issues and designs he will have with this. Dark fiber from a cable company means a point to point link. If he has multiple offices, this will generally mean that there will be a hub and spoke design on the fiber from a central location to the edge sites. In addition, the local cable co will most certainly provide the distances and loss budget for the fiber, making selection of equipment an act of trivia. The only thing not defined was the type of network he really wants, but in this case, it is also probably completely irrelevant. If you can't put all your services over TCP/IP, then you shouldn't be maintaining a network. First off, gear selection. I work for a Cisco-centric company, so most of my experience is with Cisco, but I have worked with Foundry and Nortel and a few others. If you want reliable, Cisco is certainly acceptable, and you can always put a contract on it to meet your needs. Second, protocol selection. Well, he wants TCP/IP. This will certainly be easy enough. Engineer the backend properly (IP addressing 101, and get a router for the links, your done. If you need to convert Analog Video to H.323, there are plenty of vendors who can do this. If you need COS, again, there are plenty of solutions. Layer 2 Selection. My recommendation would be to go with GigE. This is certainly cheaper than going with outdated FX technology if you buy new, and more reliable. When you have the distances and loss budget of the fiber links, you can select the appropriate GBIC's for the link, and if you get light at both ends, you have a network. In Cisco terms, I'd go with a 3550-12G at the core if you have more than 2 locations. This will be a reasonable fiber concentrator ($9,999 list) and also does QOS, policing, and routing (both packet and protocols, such as EIGRP). At the edge, depending on how much intelligence you need, you can put in Cisco 3550-24's, either EMI or SMI flavor. The EMI boxes are routers (same code as the 3550-12G. The SMI boxes have port routing in the newest code, but won't run routing protocols. These boxes will allow you to converge your network (data, VOIP, and video) and really don't have a horrible price tag. The SMI lists at $2,999 and the EMI at $4,999. This doesn't include GBIC's but the max cost on those is long-haul (Cisco ZX) which lists at $5,995. The intermediate reach LX is only $995. Don't mess around with MMF (SX GBIC's) if you don't have to. Even if you do short haul, this will be a more stable solution and will allow you to repurpose gear in the future. The big gotcha with this is support of the fiber. Most of the time Cable dark fiber contracts mean that the customer is responsible for paying for repair of the fiber. Find out who is responsible for the fiber, and make sure you budget appropriately if the cable company is going to charge you for repairs on the lines. If they won't do it, find someone who can (check the contractors who already work with the cable company, they already know the systems and people) and get them on retainer or whatever. Many schools and governments have ended up shocked because they had to find someone in the middle of the night with a fusion splicer to fix a damaged link. Or the cable company sent them an outrageous bill for repair after the fact. This sucks, because it is hard to budget for an 18-wheeler gone awry in an ice storm. If you do it this way, you can treat the fiber just like Ethernet, and be done with it. You don't have to relearn protocols, and you will have a decent growth path for the future. My networks (that look just like this!) are WAN's that I treat like LAN's, and they are easy to support. Gybrwe