[c-nsp] DS3 Nubie

[Jay Hennigan]

On 9/24/10 11:56 AM, Jeff Wojciechowski wrote:
> All:
> 
> We are considering upgrading one of our circuits to a fractional DS3 and would just like query the experts on the list to make sure that I have all my bases covered here if we go down the DS3 route as I have never touched DS3 before...
> 
> I am considering using the following equipment:
> 
> 3925 Router + NM-1T3/E3 + SM-NM-ADPTR (per http://www.cisco.com/en/US/prod/collateral/modules/ps2797/ps4909/product_data_sheet09186a008010fba2_ps282_Products_Data_Sheet.html)
> 
> That part seems pretty straightforward (but please correct me if I am wrong). Can I safely assume that since the carriers proposal doesn't mention ATM that I don't need NM-1A-T3/E3?
> 
> Then from DMARC to my router I need to use 734 type cable with 75 Ohm BNC connectors (per tread from yesterday).
> 
> Am I missing anything?

This may seem obvious to anyone who has done this before but may be
worth mentioning...

The DS-3 signal operates uses a separate co-axial cable for each
direction of transmission, so you will want a dual 734-type cable (two
BNC connectors on each end, two physical co-ax cables.)

The usual clocking, framing, etc. issues that apply to T-1 and other
serial links apply.  Exactly one clock source, framing must match on
both ends, etc.  Generally, C-bit is used for data pipes, M13 for T1s
muxed up to T3.

For fractional, you may have to work with your carrier for CSU-type
settings and the like, but this is all configurable on the Cisco gear.
Some carriers configure the CSU to make the pipe "fractional" and others
just limit the throughput in software and leave the physical media at
the full line rate.

--
Jay Hennigan - CCIE #7880 - Network Engineering - jay at impulse.net
Impulse Internet Service  -  http://www.impulse.net/
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