I am being told to get a T1 (PRI). But I have to implement it to replace our ADSL. So for now with an T1 (PRI) I can just use a standard Cisco Router and CSU/DSU for the T1, and in the future, If I wanted to break it up, I could use a demultiplexor if I wanted to use the channels for something else? Initially its just my site and the ISP. Thanks for your post, these are really helpful.
-----Original Message----- From: John Neiberger [mailto:[EMAIL PROTECTED]] Sent: Tuesday, March 12, 2002 3:07 PM To: [EMAIL PROTECTED] Subject: RE: T1 Vs ISDN PR [7:37983] This is not quite right. Yes, ISDN PRI is physically a channelized T-1. In this case you have 23 data bearing channels and one signalling channel. For data, you can order a channelized T-1 if you need to. This gives you 24 channels available for data, but they are entirely separate channels. This probably isn't very common. You will see this sort of thing with a DS3 quite a lot, though. For example, we have a few channelized DS3s coming into our building here. On our end we demultiplex them, splitting them out to their individual DS1 channels. The other data option which is most common is a clear channel T-1. This is not channelized and provides a single 'channel' at 1.544 Mbps. If you were to order a point-to-point circuit between locations, this is what you'd order. HTH, John >>> "Chris Charlebois" 3/12/02 12:43:03 PM >>> T-1 is the layer 1 standard. ISDN PRI uses T-1 for layer 1 connectivity. Therefore, whenever you say ISDN PRI, you are referring to T-1. However, not all T-1's are ISDN PRI. The "other" T-1 is referred to as CAS, channel associated signaling and, as far as I know, is only used for voice. It allows 24 channels of sampled voice. ISDN PRI (aka common channel signaling) is a digital standard and supports 23 64k "B" channels (that can carry voice or data) and 1 64k "D" channel that carries control information. Voice over ISDN PRI has the advantage of a dedicated control channel for troubleshooting and additional call information from the telephone provider. However, it has 1 less channel. So if you are ordering a data T-1, your only choice is ISDN PRI. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=38013&t=37983 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
