atcomsystems.ca/forum Forums TDM Business Telephone Systems Mitel Telephones & Systems Mitel SX-50 Changing phone lines from AT&T to others

Hello,

I am new to forum and new to Mitel PBX. However I have great amount of experience with hardware’s and software’s if that can be utilized to accomplished something I have in my mind for long time. I appreciate it if you folks experts in Mitel system can help me out.

I have SX-50 that takes 4 analog lines from AT&T. I am not sure if they are loop start or ground start. What I want is to get rid-off the AT&T (because they became extremely pricey) and replace them with digital lines (Let’s say OOMA for an example). My usage is barely minimum and with the total 4 lines I barely hit 1000 minutes per month.

Current set-up = 4 lines from AT & T -- Mitel SX-50 -- 40 to 50 extensions (1 main number and other 3 stand by)
My desire set-up = 4 lines from OOMA -- Mitel SX-50 -- 40 to 50 extensions (1 main number and other 3 stand by)

Can this be possible? If yes what exactly I needs to do? A step by step instruction will greatly help.

If you are close to Hickory or Boone in North Carolina area then I am willing to pay your service, if you wants to take this on your hands.

Thanks
S

What you want to do is possible. I highly recommend that you find a Mitel dealer, in your area, to do this work. Not knowing if you have open tip or loop start lines will have to be determined before anything else is done.

Rcaman

Thanks Rcaman!!

As far as I understand all the digital VoIP that converts to analog dial tone uses loop start. I have no clue what my SX-50 is programmed as. I expect to be a ground loop, and if so then required to change over to loop start. However this SX-50 is an old animal I am not sure what it takes to communicate. Does this system use serial or console port to login to change program?

I can not locate anyone near me who can make this simple change. Once that's done, it's no brainer to snap 2 wires using jumper to test it out. I can not even locate the operational or maintenance manual to explain how communication is being done and simple program change instruction from ground start to loop start.

Thanks

I'm not aware of any competitive service providers or VoIP devices that will emulate ground start trunks. Nobody uses these anymore, hence the high price for them from at&t. They don't want to support them either. They are difficult to troubleshoot without a seasoned technician, and we all know that those are quickly becoming a thing of the past. Loop start lines are the norm for small installations now. They have their issues as trunks on a PBX, but they can work.

The biggest risk with using loop start lines on a hotel PBX is call collision, or glare, where an incoming call can accidentally be answered by a guest dialing out at the exact same time of an incoming call. Ground start trunks (or PRI circuits) are designed to avoid this.

The SX-50 can be configured to support loop start trunks, but it is not recommended for the reason stated above. In addition, these devices often don't provide the mandatory supervisory signaling required when calls are abandoned.

I would not recommend using these devices as a replacement for PBX trunks, as they are really intended for the residential market where such strict requirements aren't an issue. I feel your pain about the cost of ground start trunks that hardly get used, but this is a classic example of the cost of doing business.

The other problem that you're facing is finding support for the SX-50. That's understandable since it has been discontinued for decades. I hate to be the bearer of bad news, but it might be time to replace it. There are plenty of small hybrid systems out there that offer hotel/motel features and you can usually retain the existing room phones. Panasonic and Vertical Communications make small systems that would be a perfect fit for a property of this size that are resonably-priced. In addition, you can take advantage of less-expensive line options, such as SIP trunking.

Lastly, we aren't able to provide the level of technical support on this forum that you're seeking. The intent of this forum is to provide end-user operational information, not to replace a technician. We would be doing you a disservice if we advised you to do something wrong and your system and business were damaged. There is certainly the installer search function here that you might want to consider.

Ed is absolutely correct. That being said, I know of several Mon & Pop motels that use Loop Start lines. I have one motel with a SX-50 that I had to convert to Loop Start lines only because the local telephone company (Fairpoint) did not have qualified technicians that could properly test open tip trunks. Every time there was a problem, they either converted them, without notifying the customer, to loop start, or they would reverse tip and ring on the open tip trunks. After many service calls to fix Trunk alarms and problems, I decided to just make them all loop start. I was, initially, concerned about glare, however, as the motel owner mentioned, the only thing his clients used the motel phone for was to receive incoming calls and they use their cell phones for outgoing calls (no motel charge) the glare problem was not an issue.

The OP really needs a qualified Mitel tech to do this work. The programming has to be changed to allow the use of loop start trunks IF the trunks are now open tip.

Rcaman

Hi EV607797 & Rcaman,

I appreciate for your feedback and sharing knowledge. I am really interested to know what system or model that support 40 to 45 extentions after reading this in your reply:

"There are plenty of small hybrid systems out there that offer hotel/motel features and you can usually retain the existing room phones. Panasonic and Vertical Communications make small systems that would be a perfect fit for a property of this size that are resonably-priced. In addition, you can take advantage of less-expensive line options, such as SIP trunking."

Can you please suggest few models I can take a look at it? I am really interested in upgrade but I do not have a clue what to look at it and who makes them. A model numbers to start with will help me a lot.



Thanks

I'm working on a Yeastar U-200 (and the U-100) with Hotel software and 32 port FXS boxes. I'll let you know next week now well it works. It replaces an SX-50 pre-MS-55 and 120 ports.



Carl

The Vertical Summit will work well in this application as well.

Thanks Carl!!
Unfortunately yeast only supports 32 analog extensions.

EV607797,
Do you have any specific model I look out for? I need at least 48 analog extensions with minimum 4 CO.

Thanks