Re: Signal Quality differences in CT1/PRI?

Jawaid Bazyar (bazyar@hypermall.com)
Thu, 28 Aug 1997 10:00:23 +0800

At 10:41 AM 8/28/97 -0500, Karl Denninger wrote:

>We get 31200 symmetrical connections with regularity over CT1 lines, and
>some 33.6kbps connections (usually not symmetrical however).
>
>We also get data rates between 44 and 50kbps regularly on K56Flex over
>the same circuits. I've seen 52kbps (the maximum for the present
>implementation) on some occasions on CT1 circuits, but that doesn't happen
>often.
>
>I've put modems into our PRI units (which are all intended for ISDN only)
>and haven't seen any appreciable difference in performance or call quality
>in either analog or K56Flex modes.
>
>The important thing is to be on the trunk side of the switch; if you insist
>on wink start trunks, you'll automatically be there (since the line side
>can't support wink start). If you have FXS-immediate start trunks (foreign
>exchange style service) you're almost always on the line side, which is
>HIGHLY undesirable.

---------------------- line0 - T1 Inband DS0 ---------------

Status: UP Framing: ESF Encoding: B8ZS PCM: u-law

Signaling: Trunk E&M wink start

And checking this morning, on a connection which started last night at
26400, I'm now doing:
Transmit Rate: 28800
Receive Rate: 28800

Boy, I love analog systems (ok, yes I'm being sarcastic ;)

I know that the switch in the area this dialup is from does not support
ISDN (when I ordered a BRI for our main office, they had to backhaul it 10
miles away). This is a long-developed commercial area (30 years plus) so
perhaps US West just has some old crappy equipment here. (I know, it's hard
to believe, eh? ;)

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