Operation Issues; Deregistering 20Xx Ip Telephones; Table 40 Ip Telephone Troubleshooting - Nortel BCM50 Configuration Manual

Registering Nortel 20XX IP telephones

Operation issues

Here are a few possible issues you may encounter, including a description of what may cause
them, and how to troubleshoot the issue.
Table 3 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.
To deregister a 20XX IP telephone from the IP record:
You can access the reset button from two locations:
1
• Resources//Telephony Resources//IP Terminal Details tab.
• Telephony//Sets//Active Sets//IP Terminal Status tab
Suggested solution or cause
If an IP telephone does not display the text
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 (cables, hubs, etc.).
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.
Firewall note: If you have the firewall filter set to Pass Outgoing and Block
Incoming Except IP Phones, this only allows IP telephony registration traffic
through, but blocks all other traffic, including H.323 calls on this interface. You
must still specify an H.323 rule to allow IP call voice traffic. Also, 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 *9 and use the
adjust the contrast.
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 Telephony, Call Security, Restriction Filters.
Restriction filters are discussed in the
Section 2: DN records
Connecting to server
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BCM50 Networking Configuration
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