Re: PM3 E1 to E1 direct connection
Charles Scott (cscott@freeway.net)
Thu, 28 Aug 1997 21:08:40 -0400 (EDT)
Kyle:
Funny, don't know if this is exactly related but we just had a problem
turning up a pair of PM3's at a remote POP. One had a T1 Frame Relay
feed on Line0 and a PRI on line1. The other had PRI's on both ports. The
PRI on the first box was showing zero errors of any kind but people
couldn't connect to it. If they did, they'd get hundreds of retrains. The
2 PRI's on the other PM3 worked great. We swapped PRI's between boxes
and the problem stayed with the first PM3.
Livingston tech support said right away to swap the lines so the T1
Frame feed was on line1 and the PRI was on line0. They said something
about how the PRI needed priority and it would only work well that way.
Didn't make a lot of sence, but switching the lines cleared up the
problem with the PRI connections.
My first question to the GTE guys when we saw the problem on the first
PRI was if there could be any network sync problems in feeding the
channels on that PRI. It of course turned out not to be the case, but
it's interesting that I felt it was a clock related problem now that I
read your comments.
Chuck Scott, Freeway
On Thu, 28 Aug 1997, Kyle Platts wrote:
> >
> >I need to connect two PM3 boxes to each other using E1 interfaces.
> >(Ethernet is busy for other needs).
> >I mean thi should be a direct connection,
> >without any telco equipment.
> >
> >Has anyone succede with this? Is it possible?
> >Thank you in advance.
>
> >I doubt it as the PM-3 has no internal clock and is completely
> dependent on an external clock for timing. If something did do timing
> it would be possible.
>
>
> Pssst - don't tell anyone, but if you have a dual T1/E1 box, if you have a clock source on line 0, line 1 will use the incoming signal on line 0 as the transmit clock source on line 1.
>
> I haven't been able to prove this, since I do not have a PM3, but it sure looks like it behaves in this manner. I have brought this to LE's attention, but have not heard anything back from them.
>
> Kyle Platts
> CSS-Tech
> !NTERPRISE Networking Services
>
>
>