Example for Configuring E&M Interfaces in the Air Traffic Control Scenario
Networking Requirements
As shown in Figure 10-4, in the air traffic control scenario, RouterA connects to the internal call system in the ACC through an E&M interface, RouterB connects to the station through an E&M interface, and RouterA and RouterB have set up an MPLS tunnel between them using the PWE3 technology.
When a traffic control person calls a person on an airplane, the air traffic control department wants E&M signals to be transparently transmitted through the established MPLS tunnel to implement the call between the traffic control person and the person on the airplane by configuring E&M interfaces on RouterA and RouterB.
Configuration Roadmap
The configuration roadmap is as follows:
# Configure the E&M interface on RouterA so that E&M signals can be transparently transmitted to RouterB through the MPLS tunnel.
# Configure the E&M interface on RouterB so that E&M signals can be transparently transmitted to RouterA through the MPLS tunnel.
Procedure
- Configure the E&M interface on RouterA.
<Huawei> system-view [Huawei] sysname RouterA [RouterA] interface serial 2/0/0 [RouterA-Serial2/0/0] link-protocol tdm [RouterA-Serial2/0/0] em passthrough enable [RouterA-Serial2/0/0] quit
- Configure the E&M interface on RouterB.
<Huawei> system-view [Huawei] sysname RouterB [RouterB] interface serial 2/0/0 [RouterB-Serial2/0/0] link-protocol tdm [RouterB-Serial2/0/0] em passthrough enable [RouterB-Serial2/0/0] quit
- Verify the configuration.
# View details about the E&M interfaces. Use the command output of RouterA as an example. You can view that the physical status and the link-layer protocol status of the E&M interface are both Up.
[RouterA] display interface Serial 2/0/0 Serial2/0/0 current state : UP Line protocol current state : UP Last line protocol up time : 2014-02-25 16:00:49 Description:HUAWEI, Series, Serial2/0/0 Interface Route Port,The Maximum Transmit Unit is 1500, Hold timer is 10(sec) Internet protocol processing : disabled L2VPN connection of the main PW is up L2VPN connection of the second PW is down Last physical up time : 2014-03-11 16:02:13 Last physical down time : 2014-03-11 16:02:13 Current system time: 2014-03-11 17:46:16 Last 300 seconds input rate 5210 bytes/sec 41680 bits/sec 100 packets/sec Last 300 seconds output rate 5009 bytes/sec 40072 bits/sec 100 packets/sec Input: 100 packets, 0 bytes Total Error: 0, No Buffers: 0 runts: 0, Giants: 0 CRC: 0, Alignments: 0 Aborts: 0 Output: 100 packets, 0 bytes Total Error: 0, No Buffers: 0 Giants: 0 Input bandwidth utilization : 0% Output bandwidth utilization : 0%