Mind the Gap... Between VoIP and Analog

Around five years ago my company made the decision that at some point in the future we would be replacing our phone system with a VoIP system.  As part of that decision we decided that it was no longer smart to run separate voice and data wiring on new projects.  This led us to a problem of how to make the connection between data patch panels and the existing voice 66 blocks.

Unfortunately we didn't go straight to the solution we are using now.  Our first solution was to take voice cross connect wire and terminate it with an 8p8c connector on one end and then punch down the other end to the 66 block.  For one or two links, this solution worked ok, but scaling the solution ended up with a rat's nest of cross connect cables.  

The next solution was basically the same as the first only we using CAT6 patch cables with one 8p8c cut off.  It was easier to keep the cabling neater, but it still didn't scale well as the thicker cables got in the way on the 66 blocks.

Finally we came to the solution that I want to share.  We started buying Panduit 24 port 1 pair voice panels.  These panels have a RJ-21 connector on the back that splits a 25 pair cable into 24 RJ45 jacks with 1 pair connected to pins 4 and 5 of each jack.  When combined with a 25-pair amphenol cable and a prewired 66 block, it makes a very modular and convenient way to bridge the gap between data and analog voice cabling. In this configuration I often put the voice panel with my switches as it serves as a "voice switch" in the rack. 

During the last five years this has served well and I believe that it will also help support our large analog deployment that will remain with our new VoIP system.  Hopefully our trial and error will help someone else out.

How to Waste an Entire Day Troubleshooting One Phone... and Then Fix It in Less Than 5 Seconds

So last week was a short one for me with the combination of the 4th of July holiday and some vacation time.  Unfortunately the last working day ended up being a rather long and frustrating day.  

Around 9am a ticket came in that one of the managers' phones was dead.  Keeping in mind that my phone system is an ancient Rolm/Siemens 9751 system, I started with the assumption of hardware failure.  My first step was to try a known good phone on the line.  Nope, still dead as a door nail.  I also tried changing the line to a different port on the system fearing that the line card could be the problem, but that also failed to change anything.

By this time I was figuring on a cabling issue.  Over the next 4 hours or so I toned and re-terminated the cabling from the phone to the PBX.  Normally this wouldn't take this long, but I kept getting tone to the phone, but the phone still refused to work so I kept repeating and segmenting the process.  Finally I believed that I had isolated the problem as being between the last IDF and the phone jack itself.

At this point in the day, the manager had already left for the day so I had to get the plant engineering director to unlock the office for me.  My plan was to re-terminate the phone jack hoping that there was a short in the wall jack.  The plant engineering director was a bit intrigued by my day of troubleshooting so he stuck around to help me move the desk out of the way.  As we were doing this, he started to trace where the line left the room and noticed that it when through a box on the wall with a switch.  I flipped the switch and bam, the phone worked again.  He explained that he recognized the switch as an old line switch (to switch a single line phone from one line to another) because his father used to work for the phone company.  

So now, that others may learn from my day of troubleshooting, here is what the switch looked like, after I added some labels for the future.  My lesson, expect the unexpected.

Phone Switch