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Installed Cabling: 2 vs 4 pairs

Hi everyone,

I've been following the 2 vs 4-pair discussion and would like to comment on
the nature of the installed base of structured cabling.

I have conducted a number of cabling surveys over the last 6 years and have
also used published market research from Frost & Sullivan and BSRIA
(Building Services Research & Information Association).

A survey presented to IEEE 802 in 1994 reported that a substantial majority
of European structured cabling was configured as 4-pairs to each outlet.
2-pair configuration was observed in Germany, where the use of individual
screened pairs was popular. Difficult to quantify the share of 2-pair
outlets at that point, but my best guess was less than 5% of all of Europe.

My estimate of the number of installed Cat 5 outlets at end 1995 was 100
million world-wide. The market grew at about 15% per annum over this
period, which suggests that the installed base may have doubled. I think
this puts the estimated installed base of 300,000 2-pair IBM cabled outlets
in perspective (I won't do the math). The deployment of 2-pair IBM cabling
has been in rapid decline for a number of years and is undergoing

UTP still dominates and 4-pair UTP/FTP cabling probably accounts for over
90% of the world-wide installed base. The vast majority of installations
are implementing the recommendations contained in ISO/IEC, European and
TIA/EIA cabling standards and terminating all 4-pairs to the outlet.

Best regards,

Alan Flatman
Principal Consultant
LAN Technologies UK