atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services T1's, CSU's and DSU's Turning a DS3 into 28 T-1's

Help!! Here's the story: Ordered a DS3 to replace 20 T-1's. It is cheaper on the network side and everybody at the ld carrier said it will work exactly the same as T-1's. Now I am being told it will not and it is due to be installed in two days. The signaling I need is d4-AMI. They want to know if it will be either ss7 or PRI. Our equipment is too old for both. How do I make this work? I have heard about using a multiplexor or a mux? But how do I know if I am getting the right one and if it will work. My equipment is based off of the D240sc t-1 rev1 dialogic boards. I also use a 1980's phone system from possibly inter-tel with the Premier logo on it. Ultimately, I need to have 28 T-1's from the DS3? Any tricks? What equipment do I need? How should the carrier set up the DS3? Thank you in advance for all of your help!

AMI D4 signalling is old. I haven't seen a B8ZS to AMI D4 converter. Your carrier is asking about protocol translations not T1 line signalling. I had to upgrade an entire PBX when SBC upgraded their CO over a weekend to Fujitsu Muxs that wouldn't support AMI D4. Good luck. Maybe someone knows of a way around it that I don't know.

Thank you for the help! The main problem appears to be taking the DS3 and turning it into individual T-1's. There has to be a way to do it. I have contacted everyone possible and have placed my faith in this forum. I have read tons of posts and you guys are awesome! What I am thinking is using a multiplexor or mux such as the mx2800 series from adtran and finding a way to make it work??? Does anyone have any clue on how to do this? I have no equipment at this point other than my dialing equipment and I am not sure what to do. Thanks again!!

Okay here we go....

The first thing you need is to get the proper equipment. Any M13 mux will break out the individual t1’s from the ds3. The Adtran MX2800 should be okay but it will need the proper configuration. Unless you have a DC power plant you will want the AC power model. I would suggest you put it on an UPS also. You also want to get the M13 control card not the STS-1. You will be using M13 framing on the DS3 not C-bit. The DS3 side of the circuit is referred to as the high-speed side. The t1 side is referred to as the low-speed side. On the t1 side you will need to physically breakout the t1’s. For the MX2800 it appears you will need a couple of accessories. It looks like you will want to get the 64-pin amp cable to the RJ48 patch panel. Your t1’s will appear on the patch panel in order, DSX-1 channels 1-28.

The t1’s are individuals and need their framing and coding set for the type of t1 on a particular channel. For instance; channel 1 on the ds3 is an sf/ami t1 so you set the mux channel 1 for sf/ami. Channel 2 is esf/b8zs so you set channel 2 for esf/b8zs, etc……….. TL1 commands are pretty basic but can get complicated very quickly. Not all mux’s use TL1 but it looks like the MX2800 does. The Manual with the mux should have the commands in it.

Basically it’s fairly simple. You have a DS3 signal on two coax cables, TX and RX. Those cables will plug in to the DS3 mux. The mux will break out the T1’s respectively to the DSX-1 panel.

This is a T3 not a bunch of t’1s. Remember, your t1 orders are ordered to arrive to you on the DS3. When you order a t1, it’s CFA (carrier facility assignment) is ordered on your DS3 and mapped on the DLR (design layout record).

Good luck

NEC used to make an M13 mux, the RC-28D. I don't know if it is still in production, but it was a nice compact unit. This is a picture of it:

https://www.teledonsolutions.com/Imgs/products/item_sales/ThreeNEC_RC28D_M13_Multiplexers.png

Our old switch site used them and they gave us very few problems.

28d's are tough as nails. you need a wire wrap gun to wire them to a dsx panel and DC power only. Line coding is set by a dip switch on the low speed cards. Easy. Although this may not be the best mux for an end user because of the DC power.

is dexman your name because you work on dsc dex switch's?

you guys are so AWESOME! Thank you for taking the time to answer my questions. Another question? What does the ld carrier have to signal the ds3 at to make it work for us?? They are asking, and I do not have the answer.

Hey SST!

Yup, you figured me out. The company I work for (a national IXC/CLEC) has used DSC (now Alcatel) DEX switches for more than 15 years [DEX-400, 600 & 600E].

Alcatel has obsoleted the DEX platform and our company is in the process of decom'ing them and installing VOIP switches.

The new switches (Sonus) are nice and compact, but the DEX's interface is much better. :thumb:

I'm not sure what is meant by "signal". :confused:

If you want to break the DS3 signal down to 28 individual DS1s, you would order a "Muxed" DS3.

If you wanted to use the DS3 as a single pipe, say for high speed data access, you would order a "Concatenated" [C-Bit] DS3.

Thanks Dex and SST. Honestly, I am not sure either. Here is the solution I am proposing and thinking will work: Use a MX2800 M13 Multiplexor with an AC Power Supply. Use an RJ patch panel to break down my 28 T-1's w/ a 64 pin to 64 pin cables. Then use 2 coax cables to connect that to the DS3. Sound good? Also I think we will get the ds3 with the SS7 signaling to run sf D4 AMI so my equipment will interface with it. What do you think? And if I have trouble with the wiring will you guys be able to give advice? You guys are the s***! Thank you!!! oh, and there is a B8zs to AMI converter out there! I had to use it on a bad install from ITC Deltacom. (They installed B8zs wehen we REPEATEDLY requested D4 AMI).