T1 Questions?

Question

Hi. I'm having trouble understanding how a physical T-1 connection would look like.

Are point-to-point T1's the only kind of T1's that exist?
Does point-to-point mean that they connect from the ISP to a location.
Does point-to-point mean that a T1 connects from location to location with the ISP in the middle of the T-1 connection?
When a customer purchases a T-1 line from their ISP, does that provide them with Internet access?

This is really confusing to me. I've tried reading it, but I don't understand. If anyone has any diagrams of a T-1 setup, that would help as well. Thanks!

Answer 1

a point-to-point T1 is between two locations.
They also have Internet T1's which is one connects to a location and the other end directly to the Internet.

Now to answer your questions directly:
1. Are point-to-point T1's the only kind of T1's that exist?
2. Does point-to-point mean that they connect from the ISP to a location.
3. Does point-to-point mean that a T1 connects from location to location with the ISP in the middle of the T-1 connection?
4. When a customer purchases a T-1 line from their ISP, does that provide them with Internet access?

1. No, their are many kinds, MPLS, point-to-point, etc.
2. No, from one point that you own to another or something like one site directly to another.
3. Yes, they provide the service to deliver T1 access from one site to another in most instances.
4. no, an Internet T1 does.

Answer 2

Microsoft seems to have a good explanation here

T1 technology has become a staple in the diet of network managers deploying WAN technologies. But its ubiquitousness doesn't mean it's bland: T1 comes in several flavors to suit different diets. For example, you can order a T1 between two locations to deliver a single channel with 1.536-Mbps throughput; a channelized T1 to connect a central site to 24 remote locations, with each channel providing 56- or 64-Kbps throughput; a T1 to deliver an ISDN Primary Rate Interface (PRI); or a fractional T1 service to deliver bandwidth in 64-Kbps steps from 128 Kbps and up between two locations.

To further confuse the issue, ordering T1 isn't as simple as just asking for T1. For instance, sometimes a T1 line will be listed as having 1.544-Mbps bandwidth; other times, 1.536 Mbps. Also, the size of a T1 channel is 64 Kbps, but often it's delivered only as 56 Kbps. Finally, sometimes T1 is referred to DS-1.

http://www.microsoft.com/technet/archive/winntas/deploy/cmpt1.mspx?mfr=true