To Troubleshoot Operation Issues; Deregistering 20Xx Ip Telephones - Nortel BCM50 Installation And Configuration Manual

48 Chapter 5 Registering Nortel 20XX IP telephones
To see the Codec data for a telephone while it is on a call: Press the
key.

To troubleshoot operation issues

A few possible issues can encounter. They are explained here, including a description of what may
cause them, and how to troubleshoot the issue.
Table 12 IP telephone troubleshooting
Problem
Telephone does not connect to
system
Slow connection between the
handset and the system
One-way or no speech paths
Change the contrast level
Block individual IP sets from
dialing outside the system.

Deregistering 20XX IP telephones

You can deregister selected 20XX IP telephones from the system, and force the telephone to go
through the registration process again.
Warning: After this feature is activated, all active calls are dropped.
N0027269 01 N0027269 01
Suggested solution or cause
If an IP telephone does not display the text Connecting to server
within two minutes after power up, the telephone was unable to
establish communications with the system. Double-check the IP
configuration of the telephone, and the IP connectivity to the system
(for example cables or hubs).
If the connection between the IP client and the system is slow (ISDN,
dialup modem), change the preferred codec for the telephone from
G.711 to G.729. See "IP telephone server configurations" on page
Signaling between the IP telephones and the system uses the system
port 7000. However, voice packets are exchanged using the default
RTP ports 28000 through 28255 at the BCM50, and ports 51000
through 51200 at the IP telephones. If these ports are blocked by the
firewall or NAT, you will experience one-way or no-way speech paths.
Note: Registration must be turned on in the Services, IP Telephony,
IP Terminals, Nortel IP Terminals, General page, before the
telephone can access the system to register.
When an IP telephone is connected for the first time, the contrast level
is set to the default setting of 1. Most users find this value is too low.
Therefore, after the telephone is installed, use FEATURE *7 and use
the or key to adjust the contrast.
UP DOWN
If you want to block one or more IP telephones from calling outside the
system, use Restriction filters and assign them to the telephones you
want to block. Restriction filters are set up under Services, Telephony
Services, Restriction filters.
key, followed by the
45.