CUCM and old fashion intercom

[power-funzl]

hi

we are living in a highrise building that is using an old style intercom system. each apartment has a standard 2wire phone connected. to call other apartments or offices, one simply dials for example 318 to get conected with office 8 on floor 31. 

I want to conect this intercom to an existing cucm. I tried to get an FXO gateway Patton 4114. but when I connect it to the intercom lines, it reboots every 10 to 15 minutes without any obvious reason.

can someone shine some light on this please?

[iLoveBGP]

Hi @power-funzl ,

Connecting an old-style intercom system to CUCM can be challenging due to compatibility issues with legacy wiring and signaling. The issue with the Patton 4114 rebooting might be related to power fluctuations or signal inconsistencies on the intercom lines.

Here are a few things to check:

1. Line Voltage and Impedance: Old intercom systems often use non-standard line voltages or impedance that can cause instability in FXO gateways. Use a line tester to measure voltage and ensure it’s within the supported range of the Patton 4114.

2. Firmware Update: Make sure your Patton 4114 is running the latest firmware. Some older firmware versions had known stability issues.

3. Power Supply: Verify that the power supply for the Patton 4114 is stable and matches its specifications. A fluctuating power source can cause reboots.

4. Surge Protection: Intercom lines can sometimes carry surges due to electrical interference or grounding issues. Adding a surge protector or isolator might help.

5. Alternative Gateway: If the issue persists, consider testing with a different FXO gateway or using an FXS/FXO combination to simulate standard telephone signaling on the intercom line.

Lastly, ensure that the intercom system wiring is properly grounded and not introducing noise or instability into the connection.

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[power-funzl]

i am thinking about option 5, an alternative gateway. what would you reccomend: I am reading a lot about grandstream... another one i was looking at was the Cisco VG400 and SPA8800

[iLoveBGP]

If you're considering alternative gateways, both Grandstream and Cisco are good options, depending on your needs. Grandstream devices like the HT813 or GXW4104/4108 are affordable and work well with legacy systems, offering flexibility for older intercom setups. On the other hand, the Cisco SPA8800 is a solid mid-tier option with FXO and FXS ports, ideal for smaller setups, and integrates seamlessly with CUCM. If you need enterprise-grade reliability and already have a Cisco environment, the VG400 is a strong choice, though it might be overkill for basic intercom integration. For simplicity and cost-efficiency, Grandstream is a great option, but for tighter CUCM integration, I'd lean towards the SPA8800.


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[Nithin Eluvathingal]

It's not the FXO gateway you need; it's an FXS gateway to connect the analog phone. You need to configure SIP trunks on the Patton gateway so that the call will be sent to the CUCM.

I have a customer who uses hotline phones with a Patton gateway, utilizing CUCM as the call control platform. For the configuration on the Patton gateway, you might need to reach out to the Patton support community.

[power-funzl]

why would I need an FXS gateway? the gateway is supposed to replace a traditional phone, which in my understanding is a FXO device.

[Nithin Eluvathingal]

FXO is for connecting the ISP line, while FXS is for connecting endpoints such as phones. If you connect a phone to an FXO port, it won't work.

[iLoveBGP]

@power-funzl 

You’d need an FXS gateway if the intercom system expects to connect to a device that behaves like a traditional phone. FXS ports provide the dial tone, power, and signaling that a phone line requires, effectively emulating the phone the intercom expects. If the intercom connects to the gateway as it would to a phone, an FXS gateway is the right choice.

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[Jerrytech1]

You might want to try a Loop Current Regulator. this will keep the line voltage going into your FXO steady and prevent lockups and drop offs. Old school technology.

[power-funzl]

the device was defective. I got a new one now which doesnt reboot continiously.

Now I am trying to get it configured. The device should provide a SIP gateway for the trunk I set up in CUCM. If CUCM connects a call to the gateway, it should dial out of FXO3. And if there is a call comming in on FXO3, it should forward it to the SIP gateway.

I think its a fairly easy setup, nevertheless I have been trying hours after hours with no luck. Anyone here that can help me on this?

[Nithin Eluvathingal]

The Patton device will establish a trunk with CUCM, which can be either SIP or another protocol supported by both Patton and CUCM. The remaining configurations on the Patton are beyond the scope of this community. Please refer to the Patton admin guide for detailed configuration instructions.