cabling and pinouts

One of the important aspects of a Vocera project that should not be overlooked in the planning phase is the cabling requirements. Different parts of the system have different requirements, likely you will need a few different cables to get your system running. Here is what we will cover today:

1) Basic Cabling
2) Ethernet Crossover
3) T1 Crossover
4) Analog

Special notes
*** I suggest you buy quality cables and put a cable tester on them prior to use.

*** You should ask your data center staff if they will provide required cables or give you their cable color requirements if they have been defined.

*** T1/PRI section assume you are NOT using CSU/DSU's.


Basic Cabling
Assuming someone reading this knows nothing about cabling we are going to start off simple. Every time you connect a PC or server to a switch you will use a normal straight through cable, sometimes called a patch cable. Both ends of this cable will terminate in the same sequence, probably like this:

It's a little blurry, but with the gold pins facing up you should see the following colors:
1 - White/Orange
2 - Orange
3 - White/Green
4 - Blue
5 - White/Blue
6 - Green
7 - White/Brown
8 - Brown

Here is a butchered cable, destroyed for your entertainment:

OK, so our straight through cable will have these same pinouts on BOTH ends! The next two cables will have these pinouts on ONE end. This means you MUST check both ends of a cable to know if it's really straight through.

For review this will be the cable type used to connect VS, VTS, and VRS server's NIC cards to their switchports.


Ethernet Crossover
The second cable we might need is an Ethernet Crossover Cable to connect our BCWS to it's AP. I say "might" because some PC's and some AP's will detect the need for a crossover cable and automatically reconfigure itself to use a straight cable as if it were a crossover. Strangely it's actually the higher end gear that assumes you will buy or cut a crossover if you need one. Because these cables do play havoc in networks by people using them where they shouldn't, I strongly suggest using a red cable for Ethernet Crossover Cables. Assuming we need one of these and didn't buy one, here is the pinouts:1 - White/Green
2 - Green
3 - White/Orange
4 - Blue
5 - White/Blue
6 - Orange
7 - White/Brown
8 - Brown

A little logic tells us that Ethernet must be using pins 1,2,3, and 6 because that is the only pair changes at one end of the crossover. OK, out of the minor leagues now. The VTS will need some special connectors for it's Dialogic card.


T1 Crossover
If you are doing T1 or PRI digital integration, you will need a T1 Crossover Cable. T1's use pins 1,2,4, and 5 so if we try to use a Ethernet Cable or a Ethernet Crossover Cable to connect our PBX to our VTS we will not be able to get our link up! Again I choose a color for this cable that makes it completely different than anything else in the data center. Lets take a peak at these pinouts:
1 - Blue
2 - White/Blue
3 - White/Green
4 - White/Orange
5 - Orange
6 - Green
7 - White/Brown
8 - Brown

If you need a "loopback plug" to test for the carrier or your PBX vendor you can simply take two pieces of wire and use one from pin 1 to pin 4 and the other from pin 2 to pin 5 crimped in the same RJ45 connector to do the job. Actually I will borrow this from Google images, thanks somebody for not making me get the camera back out.

Analog
The last bit of cabling we probably can't buy our way out of, analog integration throws us a few gotchas that need to be planned for. First off lets take a peak at our supported 12 port Dialogic card for a moment:Hmmm, only six ports for 12 phone lines.... Dialogic decided to use two lines per port. An "RJ11" jack has 6 pin positions, normally for phones only the center most pair is used, but for this application we must use 4 pins per jack, thus two lines per port. Here is how we do this.

Normally when I show up I have a run of cable coming from the PBX to the VTS server location terminated this way:
This is actually good because we can plug in a test set to each plug and test the line by calling a desk phone, we can also test our Class Of Service and make sure LD is setup and we know about any LD codes that might have been missed in discovery. Once we are done with our testing and we checked the extension numbers we have to cut these all off.

If Orange is x1001, Green is x1002, Blue is x1003, and Brown is x1004 I would want to crimp them down this way to keep logical.Now I plug Orange/Green plug into port 1, and Blue/Brown plug into port 2 and I should have four working lines, but do I? I have seen this get messed up, so now I will dial 1001, 1002, 1003, and 1004 to make sure each of them gets me "Please say the name of the person or group you would like to speak to." If one of them fails I know right where to go to look for the issue.

The very last step in analog integration is to test the hunt group. Depending on the PBX their will either be a "roll down" from 1001->1002->1003->1004 or a "hunt pilot" of 1000 with each of the four numbers assigned to it. In the first case dial 1001 four times and you should get Genie four times, or in the later case dial 1000 four times and look for the same result.


Conclusion
A few basic links to get you by:
STRAIGHT THROUGH CABLE for all servers <-> switchports
ETHERNET CROSSOVER CABLE for BCWS <-> AP
T1 CROSSOVER CABLE for VTS <-> T1 PBX port
BUT SET for testing analog lines
CHEAP CRIMP TOOL just incase you don't have any
BASIC CABLE TESTER to be sure your pins are right

You may also need a punch down tool or a tool for toning out drops, as well as an assortment of RJ11's, RJ45's, and some Cat5 cable but most places have those things laying around somewhere already, as long as you know where to look and who to ask.