Dialup congestion and winter weather (fwd)

Roeland Meyer rmeyer at mhsc.com
Thu Jan 4 18:44:27 UTC 2001


Yes, I was dialing into my own network.
No, I didn't make the connection to the weather.
Yes, it was LD from coast to coast, via AT&T calling card.
Yes, I did make the point that it was time-dependent. But, that could have
easily been a local-loop circuit dependency. Where, I got a circuit that
wasn't limited.
 
I am now back on the west coast and no longer in southern bell's region.
However, when I was there, I ran local loop tests that indicated that the
problem was on the near-end (NC). On the CA end, I consistantly get >33.6K
connections. I get similar results from CO, NV, WA, and OR metro areas
(>33.6K, consistently [I run both V.90 and 33.6K modem banks]). Only in
southern bell's regions does it drop to 14.4K (I was in Graham, NC).
 
Note: In the past 15 years, most (90%) of the bandwidth problems, using
modems, both customer and corporate, that I have had, were "last mile"
issues (IOW, local loop, usually at the end-node).

-----Original Message-----
From: Christopher Grupe [mailto:cgrupe at nortelnetworks.com]
Sent: Thursday, January 04, 2001 9:27 AM
To: Roeland Meyer; Roeland Meyer; 'multics at ruserved.com'; nanog at merit.edu
Subject: RE: Dialup congestion and winter weather (fwd)



Maybe I misunderstood the statement you made... Let me paraphrase your
original statement... 
During bad weather, at certain periods of time you experience: 
consistent 14.4Kbps connections using AT&T (ISP? or Long distance?)  Long
distance from Coast to Coast??? 
Are you just dialing into your network? 

Christopher Grupe 
Sr. Sales Engineer 
Nortel Networks, Service Provider & Carrier 
cgrupe at nortelnetworks.com 
I speak for myself! 

-----Original Message----- 
From: Roeland Meyer [ mailto:rmeyer at mhsc.com <mailto:rmeyer at mhsc.com> ] 
Sent: Thursday, January 04, 2001 2:19 AM 
To: Grupe, Christopher [DPARK:9234:EXCH]; Roeland Meyer; 
'multics at ruserved.com'; nanog at merit.edu 
Subject: RE: Dialup congestion and winter weather (fwd) 


1) I'm my own ISP, dialing into my own modem banks. I am reasonably 
confident that I know what my own systems are doing. They are not 
interacting as you describe. 

2) Local loop-back tests show that my servers see full bandwidth, on their 
last mile. Similar testing on the NC "last mile" show the bandwidth 
contraints.  Since the bandwidth is constrained on the "last mile", the LD 
trunk behavior is irrelevent. Although, that was a probability, until I did 
the tests. 

3) You really wouldn't believe the telco attachment equipment I carry in the

*other* half of my lap-top case. On the road, I can attach to the 
tin-cans-n-string communications network, if I have to. Even if it does add 
15 pounds to the carry weight<g>. 

-----Original Message----- 
From: Christopher Grupe [ mailto:cgrupe at nortelnetworks.com
<mailto:cgrupe at nortelnetworks.com> ] 
Sent: Wednesday, January 03, 2001 7:56 AM 
To: Roeland Meyer; 'multics at ruserved.com'; nanog at merit.edu 
Subject: RE: Dialup congestion and winter weather (fwd) 


He Sent, 
>-----Original Message----- 
>From: Roeland Meyer [ mailto:rmeyer at mhsc.com <mailto:rmeyer at mhsc.com> ] 
>Sent: Wednesday, January 03, 2001 12:53 AM 
>To: 'multics at ruserved.com'; nanog at merit.edu 
>Subject: RE: Dialup congestion and winter weather (fwd) 
> 
> 
> 
>That isn't the only issue. I've just found that Southern Bell does 
bandwidth 
>limiting on their residential customers. Most folks would never know the 
>difference, but when v.90 modems start consistantly connecting at 14.4K, or


>less, then I know that the telco is only allowing 32K per voice channel 
>(rather than the usual 64K). BTW, that was using AT&T universal LD from 
>Graham, NC, to Livermore, CA. I only ever got full-speed late at night. 


Come on, 
The ISP is not going to write an init script for their modems to permanently

have them connect at 14.4. Telco's don't turn down the PCM rate on dial up's

to 32KBps either... Telco's (RBOC's) have a separate (unregulated) ISP, 
which handles dial up traffic. The regulated side is the switched side 
(voice switch).... One has nothing to do with the other (usually union 
workers on the regulated side, and non-union on the unregulated side). So to

prove your point, the dial side (ISP non-union) would call the CO's and have

the Switchman changed the line card to an ADPCM (32Kbps) card at the switch,

and the ISP sets their modems to connect at 14.4Kbps. No way Jose! 

Some CLEC's are running their line cards using ADPCM (32Kbps) and over an 
ATM backbone. The RBOC's at this time are still using typical PCM (64Kbps) 
per channel, for the line cards (unless using BRI). 
The problem you may be experiencing is with the inter switched trunks, or 
coming in a span that has timing slips, Errored Seconds, and severely 
errored seconds, etc. Especially if you are going LD from NC to CA. 
Christopher Grupe 
Sr. Sales Engineer 
Nortel Networks, Service Provider & Carrier 
cgrupe at nortelnetworks.com 
I speak for myself! 

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