Issue Description

customer are having issue to register the cisco phone to Huawei switch, it take very long time (>15 mins) to register or it didn’t register at all.

Handling Process

The switch can encapsulate voice VLAN information into LLDPDUs and send them to connected IP phones. However, IP phones of some vendors send Cisco Discovery Protocol (CDP) packets. You can run the voice-vlan legacy enable command to enable CDP-compatible function so that the switch encapsulates voice VLANinformation in CDP packets and sends them to connected IP phones.

Root Cause

Cisco ip-phone send the CDP message to get ip address,  we need enable CDP-compatible function so that the switch encapsulates voice VLAN information in CDP packets and sends them to connected IP phones.

Solution

configure command "voice-vlan legacy enable" on interface to make sure switch encapsulates voice VLAN information in CDP packets and sends them to connected IP phones.

[HUAWEI] interface gigabitethernet 1/0/1
[HUAWEI-GigabitEthernet1/0/1] voice-vlan legacy enable