ds3 timing 1

[paublo]

I was talking to a VZ data tech and we started talking about
timing and i told him that i used line timing for my custermers end
and on the t1. I told him that i had my t3 set to looped (line)
timing, this is when he told me that this could cause issues and i
should set it to internal timing. as my t3 should be the master clock
for all my t1s on it.

Im using a lucent cascade switch to terminate my t3's from VZ. He told me
that the t3's should provide their own timing.

just wondering if this is the right thing to do, setting it to
internal timing on VZ ds3's.

we are running a frame-relay network and on point to point t3's from
vz

TIA, P

 

[johnpoole]

i wouldn't, i've had a lot of carriers "demand" that they had to be the clock source, one even wanted my clock source changed to his pri and it was down... he thought it wouldn't come up unless i changed my clock..

i clock off of my long distance carrier because it is the most reliable.. my backup is my locals and i have built 100's of switches the same way, merridian, rolm, mitel, seimens etc.. i don't clock off of ties unless that's my only point of contact... unless your taking slips, then refer to rule one, if it's not broke, don't fix it.

john poole
bellsouth business
columbia,sc

 

[ISDNman]

Not sure I understand your question.

Several general principles apply however, so I'll elucidate them here:

You transmit to network clock should be from the lowest status clock available.

Normally this would be the clock derived from the incoming from-network clock. However if you have a GPS clock available (or a ceisium clock) this could be used.

Many pieces of CPE have a local clock source. This is generally stratum 4, at best. Hence this is rarely the best choice, but is handy for aplications such as limited distance modems (where is no network. IN this case one unit uses its local clock and the other unit tracks that clock by treating it as a "network clock".

The clcok formt he Telco will be stratus 2 or 3, and thus is likley to tbe the best clcok available on site.

In a tandem application, where a device connects to two other unrelated devices it gets a bit more complicated. If both those devices are both Telco switches (even if different carriers) they both should be low stata clocks (Strata 2 or 3) and either can be used as master clock to transmit to both lines.

If one device is NOT a Telco then that device should iideally get clock from a line connected to the telco. If it does not have line connected directly to the telco then it should clock itself tot he clock being sent be our tandem switch that is between itself and the telco, unless a local clock source such as GPS is available. This is the closest clock to the Telco, thus following our first rule.

I hope this helps

Good luck

 

[artesian2000]

Unless you are doing a private line ALWAYS clock off the line. As ISDN said the clock in your cpe might be stratum 4 at best. As a crusty old CO tech I have fix hundreds of issues having vendors clock off me and not thier equip.