A T1 is a T1. A T1 can have up to 24 "channels" on it. For a leased line,
you can setup 1-24 of these "channels" together at either 56k or 64k
intervals to get your full bandwidth - up to 24x64k which is 1.544mbps
(actually a bit less - the rest is misc. signalling if I remember
correctly). In this case all of the "channels" which you want to use are
combined to form one fast line for data to travel across.
With a Channelized-T1, each of the 24 channels is used seperately - calls
are routed across the next available one basically and each channel's data
is seperate from anothers.
The PM3 has one or two T1 (U.S. model) ports on it. Each of these can be
used for Leased Line or Channelized-T1 (or PRI - an advanced type of CT1).
If you use both of the T1 ports for CT1's in order to do dialin like I do
then you can get 48 dialin ports on each PM3. If you used one of them for
dial in and the other for a leased line then you can only have 24 dialins.
I always use seperate routers (Cisco, Livingston ones would work fine too)
from the PM3's so I can use both PM3 T1 ports for dialin purposes.
Livingston will soon be releasing a card which goes into one of the modem
slots which has another T1 port built into it just like the one or two that
come with a PM3 chassis. This will allow you to hook a leased line up to it
AND STILL use the main two T1 ports for dialin CT1's.
Does this help any?
BTW- These T1 ports on the PM3 are RJ45 jacks which are wired into built in
CSU/DSU units and then wired into the rest of the PM3. Often times,
unfortunately, routers just have a V.35 interface which you would plug an
external CSU/DSU into - unlike the PM3.
On Sun, Feb 01, 1998 at 03:25:32PM -0800, Daniel Camacho wrote:
> I'm sorry, let me explain what I'm trying to do here.
> We are going to have 2 PM3's with 48 lines in each chassis.
> Now, this is where I'm a bit confused, the two T1 ports are for
> the digital dial-up lines which will service 48 ports. You indicated
> in your message below that line0 services your dialups. Does this
> mean you only have 24 dialup lines? And the line1 is where you
> plug your leased line connection.
>
> In my case, I need both line0 and line1 to service my dialups, but where
> do I connect my leased line? My understanding is that I get a external router
> and plug that into the ethernet port on the PM3's. Will this work? Now
> the CSU that will service my dial-up, line0 and line0 is the one built
> into the PM3. I'm wondering do I need another CSU for my leased line?
> According to MegaZone, I cannot use a external CSU with the PM3.
>
> Thanks for all the help guys. I'm just trying to figure this all out and with
> all your help, I'm getting there.
-- - Steve - Systems Manager - Community Internet Access, Inc. - Gallup and Grants, New Mexico - To unsubscribe, email 'majordomo@livingston.com' with 'unsubscribe portmaster-users' in the body of the message.