Here's a few more details -
We provision T1.
Salesdroid asks "You wanna give us $$$ for clear channel?"
Us: "..... ?"
Salesdroid: "It's so you can get 64kbit rather than the normal 56k"
Us: "We thought all DS-0s were 64kbit?"
Me: "I know! I'll ask NANOG!"
Here's a document that further obfuscates the matter for me -
http://www.comtest.com/tutorials/t1.html
Anybody care to comment on its relevance in this situation? If I read it
correctly, Clear Channel = Less Capacity. Doesn't sound right.
I believe the carrier in question is AT&T.
thanks for any input you guys might have
-carl
owner-nanog-outgoing
@merit.edu AT nxmime To: CARL P HIRSCH/Sargentlundy,
nanog@merit.edu AT nxmime@SNL-ccmail
03/22/01 12:12 PM cc:
Can anybody give me some info on what exactly "Clear Channel" means in
relation to a DS1 circut?
My gut tells me that it's only relevant with voice Ts...
thanks,
-carl hirsch
network analyst
sargent & lundy llc
If this T-1 is for internet service, then what AT&T is charging you extra dollars
for is the ability to send more data through their network (port charge). 1.536 Mbps max
data rate for clear channel, vs 1.344 Mbps max data rate for non-clear channel. There
should be no additional charge for the local loop, since all modern telecom equipment
inherently support both flavors of T-1s.
I'm quite suprised they'd offer you a data circuit that wasn't b8zs. I
think they're just using this as a way to get an extra couple of bucks per
month per circuit. Without falling into a long discorse about timing on a
DS1, the bottom line is that you get ~1.54Mbit/sec because the data stream
is manipulated to maintain timing. A non-clear channel data circuit would
only use 7 bits for data, with the 8th bit always being a 1 to maintain
timing.
Now I'm curious... Can anyone give me a situation where it would be
"better" to have a non-clear channel data circuit?
Hmm, interesting. According to folks here, there's no difference in price as
far as tariff is concerned.. Different USOC codes, though. As far as I know,
nobody here makes a difference in port cost for DS1 based on channel config,
in fact, you'd
probably get a 'are you sure you want that?!' from whoever is selling the
service to you if it is for an Internet service.
Weird. Oh well.
Here's a document that further obfuscates the matter for me -
http://www.comtest.com/tutorials/t1.html
Anybody care to comment on its relevance in this situation? If I read it
correctly, Clear Channel = Less Capacity. Doesn't sound right.
I know that most of NANOG has explained in detail about clear
channel T1s, but I thought this webpage would be a lot of help
if you never wanted to learn everything about T1s, but asked
anyway! 
www.t1.org - Standards Committee T1 Telecommunications. This
webpage helped quite a bit when I was researching about T1/T3
test patterns (which is document tr_25.pdf,"A Technical Report
on Test Patterns for DS1 Circuits").
A more specific weblink is http://www.t1.org/html/trs.htm
I'm now going to unsubscribe to nanog-post before I do something
brain dead, e.g., continue a flamewar about DNS.
FYI,
Rachel