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DS-3 extended demarc photos

  • From: Michel Py
  • Date: Fri Jul 30 12:05:13 2004

Following photos are from a customer's frac DS-3 (BW capped at 12mbps at
the DSU). The ISP is Sprint the LEC is SBC.
This is the actual demarc; this is the back of the NIU, the two black
cables in slot 1 on the right go to CPE. There is no jack of course, as
the DS-3 uses a pair of 75-ohm cables. This would be a good reason why
it is improper to call a NIU a "smart jack", as this semantic
transgression only applies to T1 circuits mostly on the east coast.
The other side of it. There is only one ds-3 circuit so there is only
one card in the NIU chassis.
A wider view where you can see the entire NIU chassis as well as the
fiber distribution panel. This is a 23-inch rack, not 19-inch.
This is an extended demarc, here you can see the equipment the LEC
brought into the customer's data room. They spliced the fiber in the
MPOE and installed their own 23-inch rack in the customer's room; this
is the preferred way of extending the demarc: move the NIU into
customer's territory. The optical platform is a Nortel OPTera Metro

Interesting points:
- This is a 1-tenant building, which helps a lot in having the demarc
extended. What also helps moving the demarc is a 120 degrees F
temperature in the MPOE and 68 degrees in the data room :-D
- The LEC brought an OC-12 ring (600 mbps) although the customer is
using only 12 mbps; room to grow.
- The equipment can't be powered by the span (power-over-fiber,
anyone?). The phone company does not trust anyone for power and even
though the entire room is on UPS and the customer also has a huge diesel
generator, they bring batteries. Note that like most telco gear
everything runs on redundant 48VDC power.


Hi-res here: