ataylor Posted December 10, 2015 Posted December 10, 2015 We currently have 35 phones on site 3 of which are IP phones. The IP phones have been working "ok" until recently, the handsets lag when entering numbers often missing digits. If anyone phones me internally the call either drops or no voice can be heard either end and on occasion the phone won't even register to the phone system (no sip server found) I am confused what is causing this. I would assume that it is a QoS issue although when a call does actually make it through, the quality of the conversion is fine. We are currently on a NEC system.
ataylor Posted December 10, 2015 Author Posted December 10, 2015 Via The telephone company that installed it - currently pestering them, but they are going a little slow..
cpjitservices Posted December 10, 2015 Posted December 10, 2015 Ah I see. Have you got access to the PBX ? Can you re-provision the phones.?
ataylor Posted December 10, 2015 Author Posted December 10, 2015 I do have access, but i'm not confident enough in my knowledge to start playing with the configuration.
JordanT91 Posted December 10, 2015 Posted December 10, 2015 As cpjitservices said, do you have support? Either with NEC or installers? If not, the first thing I'd do is a reboot of the SIP server/PBX and see if things improve. Failing that, I'd try to run wireshark to see the volume of packets going to the phone. Easiest way to do that is to mirror the switch ports the phones are connected to. It's quite possible that the phones are faulty and are spewing traffic to the SIP server/to each other. I suppose it could be a non-network fault with the phones but if it's happening on all 3 I'd lean towards a network issue.
ataylor Posted December 10, 2015 Author Posted December 10, 2015 (edited) It is connected to a GS727TP Netgear switch in my office which then links to a Cisco SGE2000 of which the PBX is connected to. Edited December 10, 2015 by ataylor
ataylor Posted December 10, 2015 Author Posted December 10, 2015 I have also tried connecting my phone to the same switch as the PBX but no difference there.
cpjitservices Posted December 10, 2015 Posted December 10, 2015 Could always try connecting the phones into the switch which the PBX is directly connected too.. Whoops seems we posted at the same time lol I'd pester the phone company to try and get a resolve.
ataylor Posted December 10, 2015 Author Posted December 10, 2015 I'm going to restart the system again tonight, i'm also tempted to move the pbx to a less busy switch.
MatthewL Posted December 10, 2015 Posted December 10, 2015 Is your voice on a seperate VLAN or have you got any QOS set for voice traffic?
ataylor Posted December 10, 2015 Author Posted December 10, 2015 (edited) Neither... From what i've read the Vlan is just for isolation - not performance, which I didn't really see the point of doing for 3 phones. Actual call quality is fine when the phones are working. although my handset does get progressively more "buggy" the more the network is under load, for example when I image a classroom. Just reset the PBX again and its suddenly kicked into action?! Edited December 10, 2015 by ataylor
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