Quoting C F <[EMAIL PROTECTED]>:
Do the Digium cards have a built in CSU?
Is a CSU an FCC requirement? or just a carrier requirement?
if you expect things to work you need one regardless of regulations,
yes the digium cards have it built in, as do most modern t1 cards.
if the "T1" terminates in something that looks like a scsi connector
you have an hssi interface most likely, if it terminates in an rj45,
especially if it has status lights, you most likely have yourself a
csu built in, sometimes you'll have a db15 instead of the rj45
depending on the country it was designed for but it still works the
same if you just get a passive adapter to get to the connector type
you need (or make one, t1 speed is a 1/8th of the slowest ethernet so
construction technique is not too critical if you ever made an
ethernet cable)
coming in from the raw copper pair this is what needs to be there :
telco supplied "pairgain" box which is normally an HDSL modem that
gets you from a type of dsl circuit to a 2 pair T1 / DS1 circuit
(don't confuse DSL and DS ONE in this sentence)
that is the actual demarcation point.
then comes your csu/(dsu)
This is the point where remote loopback tests can be done without
actually talking to the guts of your hardware, telco can normally do
it to their box as well but when they do a line test they loop to your
csu normally.
next comes a serial interface of some sort, in a more modern setup its
indivisible from the csu, in the old days you had a physical
synchronous serial cable between running at t1 clock speed.
Where its separate the serial port is also known as an hssi connection
or high speed serial interface.
So without the csu in the mix converting the t1 channel frame encoding
down to the actual serial data, you have no way to talk to the channel.
its like saying I have a usb port, do I really need the ethernet
dongle in order to plug it into an ethernet jack ? Then again some
hardware has an ethernet jack right on it, but it still has all the
same ethernet hardware as the dongle in there somewhere even if there
is no physical usb path between the pci bus and the ethernet, it still
accomplishes the same thing.
the csu is sort of like the part of the modem where the start and stop
bits are added into the actual data before hitting the actual modem
proper where the bits are converted to tones, we don't generally make
the distinction on that part of the circuit since the rest is useless
without it.
TIA
_______________________________________________
--Bandwidth and Colocation provided by Easynews.com --
asterisk-users mailing list
To UNSUBSCRIBE or update options visit:
http://lists.digium.com/mailman/listinfo/asterisk-users
Jon Pounder
_/_/_/ _/ _/ _/ _/_/_/ _/ _/ _/_/_/_/
_/ _/_/ _/ _/ _/ _/_/ _/ _/_/
_/ _/ _/_/ _/ _/ _/ _/_/ _/
_/_/_/ _/ _/ _/_/_/_/ _/_/_/ _/ _/ _/_/_/_/
Inline Internet Systems Inc.
Thorold, Ontario, Canada
Tools to Power Your e-Business Solutions
www.inline.net
www.ihtml.com
www.ihtmlmerchant.com
www.opayc.com
----------------------------------------------------------------
This message was sent using IMP, the Internet Messaging Program.
_______________________________________________
--Bandwidth and Colocation provided by Easynews.com --
asterisk-users mailing list
To UNSUBSCRIBE or update options visit:
http://lists.digium.com/mailman/listinfo/asterisk-users
