From: Jason Gardiner (gardiner@xxxxxxxxxx)
Date: Fri May 18 2001 - 13:10:02 GMT-3
A DACS is a digital cross connect that provides the ability to Mux and
Demux DS-Xs at the LEC POPs, as well as electronically map the
circuits. The fractional circuits are actually broken out of a 1/0
(DS-1 to DS-0) DACS, which is probably why the always provide clocking.
The 3/0 (DS-3 to DS-1) DACS do much of the same thing at a higher
level. All circuits from Tier 1 providers should be using these
devices, although I guess that other providers don't use them if you
have to provide the clocking ;)
Hope this helps.
Ron.Fuller@3x.com wrote:
>
> Really? I have installed many T-1s and never had the telco provide
> clocking any time other than when the circuit was fractionalized. As
> the risk of sounding ignorant, what is a 1/0 or 3/0 DACS?
>
> Gotta love this job! You learn something new every day.
>
> Thanks,
> Ron Fuller, CCIE #5851, CCDP, CCNP-ATM, CSS Level 1, CCNP-Voice, MCNE
> 3X Corporation
> rfuller@3x.com
>
> Jason Gardiner
> <gardiner@sprint.net> To: Ron.Fuller@3x.com
> Sent by: gardiner@sprint.net
> cc: Jeongwoo Park
> 05/18/2001 11:48 AM <jpark@wams.com>,
> ccielab@groupstudy.com
> Subject: Re: point to
> point T1 troubleshooting.
>
> If
> > this is a full T-1 then one of the CSU/DSUs will provide clocking.
>
> This is not necessarily true. If telco breaks out a circuit through a
> 1/0 or 3/0 DACS, then neither of the CSUs should provide clocking, as
> the DACS is tied into a Stratum-1 clock. This is the most common
> setting.
>
> Ron.Fuller@3x.com wrote:
> >
> > Was the circuit working previously and this is a new problem, or is
> this a
> > new install? You might want to check the clockings of the CSU/DSUs.
> If
> > this is a full T-1 then one of the CSU/DSUs will provide clocking.
> If it
> > is fractionalized, then both the of the CSU/DSUs should get their
> clock
> > from the telco. Can you loop the remote CSU/DSU? Do you have a T-1
> > loopback plug? Try connecting it to the cable running from the
> CSU/DSU to
> > the smartjack the telco put it and see if the line comes up. You
> can then
> > run extended pings using all 0's and all 1's as the pattern to see
> if
> > there are any cabling problems. You can do the same extended ping
> if the
> > remote loopback works on the CSU/DSUs to test the telco circuit.
> >
> > Good luck!
> >
> > Ron Fuller, CCIE #5851, CCDP, CCNP-ATM, CSS Level 1, CCNP-Voice,
> MCNE
> > 3X Corporation
> > rfuller@3x.com
> >
> > "Jeongwoo Park" <jpark@wams.com>
> > Sent by: nobody@groupstudy.com
> > 05/18/2001 10:58 AM
> > Please respond to "Jeongwoo Park"
> >
> >
> > To: <ccielab@groupstudy.com>
> > cc:
> > Subject: point to point T1 troubleshooting.
> >
> > Hi all
> > Have anyone troubleshootted T1?
> > it is ppp encapsulation, leased line.
> > LEC(local exchange carrier) said circuit is fine, which I doubt.
> > Router config is fine, I believe.
> > here is output of "sh int s2/0"
> >
> > #sh int s2/0
> > Serial2/0 is up, line protocol is down
> > Hardware is M4T
> > Description: Leased Line to branch
> > Internet address is 10.10.14.86/30
> > MTU 1500 bytes, BW 2048 Kbit, DLY 20000 usec,
> > reliability 255/255, txload 1/255, rxload 1/255
> > Encapsulation PPP, crc 16, loopback not set
> > Keepalive set (10 sec)
> > LCP Listen
> > Closed: IPCP, CDPCP
> > Last input never, output 00:00:03, output hang never
> > Last clearing of "show interface" counters 18:08:32
> > Input queue: 0/75/0 (size/max/drops); Total output
> > drops: 0
> > Queueing strategy: weighted fair
> > Output queue: 0/1000/64/0 (size/max
> > total/threshold/drops)
> > Conversations 0/1/256 (active/max active/max
> > total)
> > Reserved Conversations 0/0 (allocated/max
> > allocated)
> > 5 minute input rate 0 bits/sec, 0 packets/sec
> > 5 minute output rate 0 bits/sec, 0 packets/sec
> > 0 packets input, 0 bytes, 0 no buffer
> > Received 0 broadcasts, 0 runts, 2368 giants, 0
> > throttles
> > 8940 input errors, 1913 CRC, 0 frame, 6028
> > overrun, 0 ignored, 999 abort
> > 13556 packets output, 189784 bytes, 0 underruns
> > 0 output errors, 0 collisions, 3438 interface
> > resets
> > 0 output buffer failures, 0 output buffers
> > swapped out
> > 3672 carrier transitions DCD=up DSR=up
> > DTR=up RTS=up CTS=up
> > **Please read:http://www.groupstudy.com/list/posting.html
> > **Please read:http://www.groupstudy.com/list/posting.html
> --
> Thanks,
>
> Jason Gardiner
> Engineering Services
> Sprint E|Solutions
>
> "The only thing to prevent what's past is to put a stop to it before
> it
> happens."
> - Sir Boyle Roche
-- Thanks,Jason Gardiner Engineering Services Sprint E|Solutions
"The only thing to prevent what's past is to put a stop to it before it happens." - Sir Boyle Roche **Please read:http://www.groupstudy.com/list/posting.html
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