atcomsystems.ca/forum Forums Other TDM Phone Systems Other Telephones & Systems Now work with an AT&T 5ESS

I never thought this late in my career I'd be working with an AT&T 5ESS! Of course it's being decommissioned, but it has at least a few years to go, which at that point I may be retired. The site as ISDN/Avaya 8510 phones that I've worked with before with a previous company's Definity PBXs. Also didn't think I'd use Procomm again! It all comes back to me.

I wonder - does anyone here still work with the 5ESS?

I don't work with the switch itself, but I work with a bunch of ISDN/BRI and PRI customers in the DC metro area that are still using them. Where I live in NC, even the local independent telco uses the 5E and remotes just about everywhere. They were put in when Sprint owned the territory in the late 80s. In this area, I only work with them for ISDN/PRI and POTS customers, but they sure are reliable from a service and troubleshooting perspective. I'm going to hate to see them go.

LINK: CAROLINA TELEPHONE, A.K.A: CENTURYLINK

When I worked for Global Crossing back in the early 2000's, AT&T Local had a 5E in the same building as us. I didn't have the opportunity to walk around the rows of frames, but it seemed like a good switch from what their technicians said. We had a DSC DEX-600E, Nortel DMS-500 and later a Sonus packet switch.

Verizon has a 5E in my town, but it is going to be coming out of service once the Copper OSP Retirement project is completed. It is my understanding that Nokia is now supporting the 5E

one of the main switches in Cleveland is a 5ESS
https://www.telcodata.us/view-switch-detail-by-clli?clli=CLEVOH6262F
the other is a DMS100

Sounds like there's still quite a few 5ESS systems around. Yes, they're now supported by Nokia. We've got many ISDN and or Avaya 8510 phones on the system. Unlike the 8510s on the Avaya PBXs I've worked with, these are powered by a power supply typically in the IDF closet. I was surprised that the branches in other parts of the state don't have a 5ESS on site in their buildings, but are served by the local CO, including 8510 phones. Those use a 'U' interface card, meaning 2 wire. At the site there's an NT1 interface that converts that to 4 wire to the phone (+ the power pair). Some of the more remote buildings at the main site use the U interface, while closer runs use 4 wire, or a 'T' interface.

Interesting copper retirement projects are going on that will make a CO like this pretty much obsolete. In the mean time, good to know there's still a place for tip & ring and older telecom guys like me. Of course I work with VoIP, but the old switches will be around for a while. The voicemail system is Cisco, Octel up until several years ago.

Ironically, the BOC in this state (Southern Bell/BellSouth/AT&T) uses DMS offices almost exclusively. For some odd reason, upon divestiture, BellSouth elected to distance itself as far as possible from AT&T. They did so as far down as OSP hardware purchases. I'm not sure how they handled embedded iSDN/BRI accounts. Since most government agencies that I've ever encountered used CO-based Centrex services and ISDN phones, I'd think that somehow these sets continued to be supported by these DMS switches. Does anyone know if the DMS could emulate ESS protocol? I'm sure that since ISDN is a universal standard, it must have been possible.

Then years later, Bell South acquired AT&T. Go figure.

Interesting Bell South acquired AT&T! Don't know if an AT&T ISDN phone would work on a DMS. There are some limitations with the particular 5ESS I work on, such as no name display. I don't recall if the AT&T Definity and Prologic systems had a name option with the extension.

An option I never heard of with the PBXs is multipointing. Two ISDN sets can use the same LEN, or port. The SPID in the phone, 01(7 digits)0 designates which extension it is. Makes sense with BRI being 2B+D. A SPID isn't necessary with one phone on a LEN. I haven't installed one, but the frame tech says the 2 pairs from the LEN are just paralleled. Practical initially, but with moves/changes and one of the phones moving to a different building or even just a different floor will mean the multipoint will need to become separated.

Southwestern Bell bought out AT&T and took the AT&T name in 2005. They acquired Bell South in 2007.

That's what I thought, Bill. I knew something didn't seem right with the talk of BellSouth buying AT&T. Thanks for the clarification.