Archive for May, 2008

Analog in a digital world

Analog just won’t die … at least when it comes to voice applications.  As much as I would like to declare it dead, we still provide analog telephony services at work for things like remote access and faxing.  Most of our users have moved away from modems in favor of VPN over broadband for remote access.  Likewise, scanned PDF attachments are replacing the fax machine.  But like so many aging technologies, we hate to let go.  Analog is still holding on.

The company I work for is moving in a couple months.  As part of that move, we are replacing our Avaya PBX with Cisco Unified Communications Manager (f/k/a CallManager).  Our structured cabling is Commscope Systimax GigaSPEED XL (2081 CAT6).  Our switching infrastructure is Cisco Catalyst 6500 series (in the MDF and the IDF).  If that sounds like another language to you, just understand that it is a high-speed network that is designed to support the demands of voice, data, and video.

In the shadows of this high-speed network lurks a very low-tech solution that exists just to keep analog alive.  What for?  The fax machine is the main reason.  To keep our options open, we have allowed for up to 24 ports of analog service per floor.  We are centralizing a stack of Cisco VG224s in our MDF.  A VG224 is essentially an analog voice gateway that supports MGCP and H.323.  We will connect the amphenol RJ21 on each VG224 to a 110-block to create a cross-connect field.  The other side of the field is a 110-block where we have terminated our riser cable.  When you get to each IDF, everything terminates to a standard patch panel.  This will allow us to turn any station cable into an analog port through patching in the IDF.

Our friends at Cisco don’t provide that Amphenol RJ21 cable with the VG224.  This makes sense since the potential uses of the appliance are quite vast.  So I set out to find a male RJ21 cable that had one end unterminated (blunt cut).  After some unsuccessful Google searches, I turned to  If you have never used Blackbox before, they have just about everything you can imagine for voice and data networks.  They had just what I needed – I put an order in for 5 of these cables.  I’ll post some pictures once the cables come in and we finish the terminations.

Why do I wish analog would die?  It is expensive to maintain support for it.  Each VG224 is about $3000.  Add to that the cost of the separate cabling infrastructure and the labor to install it.  The costs add up quickly.  Maybe by the time we do our next major office move analog will be dead.  Long live the TCPIP packet!

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Memorial Day

Tomorrow is Memorial Day – a day set aside to remember fallen U.S. soldiers – all those who perished while in the service of their country.

Many nations have a monument to unknown soldiers.  In the U.S., it is the “Tomb of the Unknowns” at Arlington National Cemetery.  For my friends in Brazil, it is the “Monument to the Pracinhas” in Rio de Janeiro.  In every corner of this planet countries pay tribute to those “Known But To God”.

Tomorrow we will remember all soldiers – known and unknown – who paid the ultimate price for our freedom.  Let us pray for peace.  Let us pray for the safe return of our troops.

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