Problem Description

1. Networking: Video server - OSN2500 ( SSN2EFS0 ) - OSN2500 ( SSN2EFS0 ) - Gigabit switch - Gigabit switch - -Video matrix -Monitor/TV wall

2、Transmission is configured on the Ethernet leased line service, the external port is set to access attribute

3、The user's purpose is to transmit the service of transmitting the video server, realize the multicast function on the Gigabit switch, and copy the service to be displayed on the monitor and TV wall at the same time.

Phenomenon: The monitor and the TV wall cannot display the video service at the same time, but it is normal when they are displayed separately.

Warning message

None

Processing

1、The first reaction is that it has nothing to do with transmission, because what we configured is leased line service, which only realizes service transmission, and the multicast function is realized on the switch, and it feels that it should be a configuration error of the switch, but the user said that the multicast function can be realized normally after getting rid of the transmission.

2. Ask the user whether the multicast protocol frame has VLAN, the user verified that it does have VLAN, and instructed the user to modify the external port into Hybrid, and then the monitor and TV wall can be displayed at the same time.

3. The reason is obviously that the switch cannot receive multicast protocol frames because the service does not carry VLANs while the multicast protocol frames carry VLANs.

Root cause

Multicast cannot be realized for some reason

Recommendations and Summary

1, this problem if another way to say that by transmitting the same port of a business is normal and another business does not work, I believe that we can immediately locate the cause of the failure, and because of this problem involves the concept of video servers and multicast, etc., so that people feel that it may be more complex, but in fact to find out the key points, the problem is still very simple

2, Ethernet leased line service, only to achieve the function of service transmission, there is no open multicast protocol, while the Ethernet LAN service, if the single board support can open the multicast protocol, the specific role can be simply understood as a copy of the service on the transmission, unlike the case, is to achieve the replication of the service on the switch!