IP phone beeps

[jgscu]

We have 3 IP Dterm phones at one location that go through our VPN router and over a point ot point T1 to our main site phone system (NEAX 2000 IPS). We are experiencing 4 successive beeps intermittently on those phones. We have a second location where one IP phone never beeps but the second IP phone at the second location drops calls, goes offline, and beeps all the time.

We contacted NEC and they said the beeps are signals that mean there is packet loss. How can we fix this issue?

Is our configuration to blame? The HP switch with QoS w/ DSCP is not VLANNed then goes out through our Cisco router.

What is a suggested configuration with our setup?


thank you

 

[smoom]

Sounds like you are having a large amount of packet loss, if you are not familiar with how to troubleshoot network issues I would suggest you find a qualified company to help. There are so many variables that could be causing the issues you are describing.

 

[keypad]

There was a version that did this at default. If you log into the phone there should be a RTP Alarm option that needs to be set to off. I do not remember exactly where the option is, it may be in the adminstartor menu somewhere. But I do remeber that version 2.81 did not have the option and you will need to upgrade to at least 3.08.
I am assuming you know how to get into the IP phone setup. If not let me know.

 

[jgscu]

I do not know how to get into the phone, can you provide some help? Also, how do you check which version?

Thanks

 

[belevedere]

At the phone, press Hold, Transfer, *, #. Then press Hold, #, *. Using the soft keys, scroll down to option 0. Then scroll down to option 6 RTP alarm. Select the off option. Then using the soft keys press OK, option 0, Exit, Save.

 

[jgscu]

I do not see an option 0. I see an options 1-9. The software version is 3.12.

To get rid of the beeps, turn RPT off? How is this done with this version?

Thanks

 

[smoom]

I think you are missing the point here, the phone is beeping because you are having network issues thats what the alarm is for. Fix the issues and the phone will stop beeping.

 

[jgscu]

smoom, I appreciate your help very much.


I placed a sniffer on our network. I see an issue with the IP phone going to the destination address which is the CPU.

It states the protocol ICMP has the destination as unreachable and the port unreachable. It does not state what port it should be but gives the error of type 3 and code 3.
Currently the UDP port is 3462 (source) and 10030 (destination).

The header checksum is incorrect.It says it should be 0x2025. If you need more information I can provide it.

Should we use a different port? Is so what configuration do you recommend?

 

[pave35]

You need to implement some sort of QOS. If you have a true P2P T1 simply set priority for the VOIP in the router. There are a number of ways to do this. If you use either of the differential services (IP Presedence or Diffserv) you will need to assign the values in the PBX. Other wise you can just prioritize on the port or IP address.
The ICMP unreachable will occur from time to time when the CPU isn't quite ready. The phone will re-issue and it will all gell after 1 or 2 attempts.

 

[jgscu]

pave35,

We have DiffServ set at priority 7 on the POE switch. When you say values on the PBX, do you mean the CPU? We have it set on the port and IP address level currently on the switch.

We have the phoen going through a swithc then out the VPN router across the T1 to the CPU on the PBX.

I think something is missing in the VPN router in terms of the port configuration. If DiffServ is set on the switch, does it have to be set on the VPN router going out to the (across the T1) then to the CPU on the PBX as well? (The PBX is at a different site).

 

[pave35]

Why are you using a VPN on a point to point T1?
Or is this really a T1 to an ISP at both sites?
Also a switch is a layer 2 device and does not provide or utilize (or even see) layer 3 services such as difserv and IP Presedence. Are you talking about a priority within a VLAN maybe?
Maybe you have a layer 3 switch/router in which you could invoke QOS with diffserv but you should not use priority 7 as this is used for network control messages between network equipment. The most sensible setting would be Assured Forwarding (Diff code 46) for voice and voice control messaging.