+ 0 Votes I'd opt for Cat5e or Cat6 ManiacMan 6 years ago I'm no telecomm expert, but all the VoIP installs I've seen to date all used Cat5e or Cat6 twisted pair cable because it can sustain gigabit speeds without signal degradation. + 0 Votes perfectly clear to me! mikey.g.0727 6 years ago Your post makes perfect sense to me, because I am familiar with a 66 block. It should be pointed out, that 66 blocks come in 2 flavors (that I know of), split and unsplit, while all 66 blocks have rows of 4 contacts, connectivity is as follows- Split - a a b b c c d d e e f f Unsplit - a a a a b b b b c c c c d d d d On a split block, you use bridge clips over the 2 middle contacts, to connect the outermost contacts on a given row. i think it is strange these things are so hard to find good info on. I think its because most of the time in a big installation this would be done by an electrician who wires teleco / data, and those jobs are usually apprentice-ship type of profession. Ther are 100 million web sites that describe the pinout of a cat 5(e) so you can crimp your own cable, but almost none that tell you what do do with the cable when its done :-P If anybody has any other tips / tricks / good info sources on this type of stuff for wiring Data / Voce - post em up. Another tid-bit for ppl doing wiring in small offices - Plenum Vs PVC Cat5(e). "standard" cat 5e outer jacket is made of PVC, which when burned, releases toxic fumes. Because of this, MOST local codes require use of plenum cable, the coating does not release such fumes (but the cable costs a lot more ) + 0 Votes Question Michael Kassner Contributor Updated - 6 years ago Just to make sure, are you going to run VoIP over the Cat5/6, or are you referring to normal PBX digital lines or even analog lines over Cat5/6? VoIP requires the normal two twisted pairs per line, where as PBX digital and analog require a single pair per line. So with a typical Cat5/6 cable you could run 1 VoIP line or 4 PBX digital and analog lines. I better qualify that statement slightly, I have on occasion been required to run two Ethernet/VoIP circuits on one Cat5/6 cable, but do not recommend it as there is an elevated potential for cross-talk. + 0 Votes Answers, hopefully Michael Kassner Contributor Updated - 6 years ago When running voice over Cat5, should you typically run 1 phone line per Cat5, or multiple lines per cable? ..That is up to you, up to 4 pairs/lines can be run over one Cat5 cable. I typically use as many pairs as possible on each cable to save money. I think we need to describe a simple telco setup in a bit more detail. I hope this may help explain. PBX | >-PBX 66 cross connect ??...| ??...>- Backbone run to remote location ??.???.| ??.???.>-Remote 66 cross connect ???????..| ????????>- Individual phone trunk lines The 66 cross connect is a punch down block that allows you to easily connect all of the pairs coming from two different sources and interconnect them. The backbone run can be anything from a Cat5 cable with 4 pairs or a special telco cable with up to 50 pairs (I think). That type of cable is used to run multiple lines between telco closets or to remote locations. It saves money rather than running individual cables. If one line per cable, what is the proper thing to do with the un-used pairs on the telephone block in the closet? ..They are typically wrapped around the outer sheath or you can punch them down to keep in reserve. You may want to add another line to that location, such as for a phone that can handle multiple lines. If multiple lines per cable, what is the best way to break out the lines on the users side to connect to telephones in a neat way? ..The best way to break out the other lines is by using the 66 cross connect and then running individual cables to the phone jack, that could be Cat3 or Cat5. I guess it may not make sense but the cable from the last 66 cross connect to the individual phone jack will have unused pairs. Unless you want to daisy chain from one phone jack to another one, rather than run a completely different cable from the 66 cross connect.