Hello everyone,
Today I will share with you how to connect the AR with an optical transceiver using an E1 leased line.
Overview
Concepts
The E1 system is recommended by the International Telecommunications Union Telecommunication Standardization Sector (ITU-T). An E1 interface, working at a rate of 2.048 Mbit/s, complies with the G.703 and G.704 standards. The E1 system is mainly used in Europe and China. A CE1/PRI interface is a physical interface in the E1 system, which can transmit voice, data, and video service packets. A CE1/PRI interface can work in E1 mode (unchannelized mode) or CE1/PRI mode (channelized mode).
In E1 mode, a CE1/PRI interface works at a rate of 2.048 Mbit/s without timeslot division. Similar to a synchronous serial interface, a CE1/PRI interface supports link layer protocols, such as the Point-to-Point Protocol (PPP) and Frame Relay (FR), and the Internet Protocol (IP).
The CE1/PRI interface working in CE1/PRI mode functions as either a CE1 or PRI interface. In CE1/PRI mode, the 2 Mbit/s transmission line of the CE1/PRI interface is divided into 32 timeslots at a rate of 64 kbit/s. The 32 timeslots are numbered 0 through 31, and timeslot 0 transmits synchronization signals.
Application Scenario
To connect to a transmission network through a 2 Mbit/s E1 leased line, configure a CE1/PRI interface to work in E1 mode. As shown in Figure 1, the headquarters and branch of an enterprise are connected through the transmission network of a carrier. The enterprise leases a 2 Mbit/s E1 line from the carrier.
Figure 1 Connecting to a transmission network through an E1 leased line 
Configuration Notes
Table 1 lists the product models and versions applicable in this example.
Table 1 Required product models and versions | ||
Device Vendor | Product Model | Version |
Huawei | AR2220 | V200R001C00 and later versions |
Rai*** | RC832 optical transceiver | - |
Networking Requirements
As shown in Figure 2, the enterprise branch and headquarters are connected through a transmission network. E1 links are provided on the transmission network to connect to the branches, and optical fibers and optical transceivers are used to connect to the enterprise network. To be specific, RouterA is the gateway of the enterprise branch and is connected to optical transceiver 1 through an E1 leased line. RouterB is the gateway of the headquarters and is connected to optical transceiver 2 through an E1 leased line. The optical transceivers are then connected to the transmission network using optical fibers.
The customer can select appropriate E1 interface cards and E1 cables based on the device requirements and network environment. This example uses two-port 2E1/T1-M interface cards that work in E1 mode. 2E1/T1-M interface cards work with DB9 connectors, while optical transceivers work with RJ45 connectors. 120-ohm DB9-to-RJ45 cables can be used to connect 2E1/T1-M interface cards with optical transceivers, which are then connected to the transmission network, enabling data transmission between the branch and the headquarters.
Figure 2 Networking for configuring two routers to communicate through optical transceivers
Data Plan
Item | Parameter |
|---|---|
The working mode of the 2E1/T1-M interface card | e1-data (CE1/PRI mode) |
The working mode of the CE1/PRI interface | E1 |
Clock mode of the CE1/PRI interface | Slave |
The IP address of the CE1/PRI interface | 10.1.2.1/24 |
Item | Parameter |
|---|---|
The working mode of the 2E1/T1-M interface card | e1-data (CE1/PRI mode) |
The working mode of the CE1/PRI interface | E1 |
Clock mode of the CE1/PRI interface | Slave |
The IP address of the CE1/PRI interface | 10.1.2.3/24 |
Configuring Routers
Configuration Roadmap
The configuration roadmap for RouterA is as follows:
Configure the 2E1T1-M interface card to work in CE1/PRI mode.
Configure the CE1/PRI interface to work in E1 mode.
Configure other parameters of the CE1/PRI interface, such as the cable type and clock mode.
The configuration roadmap for RouterB is as follows:
Set the parameters of the CE1/PRI interface to the same values as RouterA.
Procedure
Configure RouterA. (The configuration of RouterB is similar to that of RouterA.)
1. Configure the 2E1T1-M interface card to work in CE1/PRI mode.
<Huawei> system-view
[Huawei] sysname RouterA
[RouterA] set workmode slot 4 e1t1 e1-data
Warning: The specified work mode is the same as the work mode that has been configured. Please reset the board to take effect first.
2. Configure the CE1/PRI interface to work in E1 mode.
[RouterA] controller e1 4/0/0
[RouterA-E1 4/0/0] using e1
Info: This operation may take a few seconds. Please wait for a moment......succeeded.
3. Configure other parameters of the CE1/PRI interface, such as the cable type and clock mode.
[RouterA-E1 4/0/0] line-termination 120-ohm
[RouterA-E1 4/0/0] clock slave
[RouterA-E1 4/0/0] data-coding normal
[RouterA-E1 4/0/0] idlecode 7e
[RouterA-E1 4/0/0] itf type 7e
[RouterA-E1 4/0/0] undo detect-ais
[RouterA-E1 4/0/0] quit
4. Configure the IP address for the serial interface.
[RouterA] interface Serial 4/0/0:0
[Router-Serial4/0/0:0] ip address 10.1.2.1 24
[RouterA] quit
5. Check the configuration.
# Check the status and parameter settings of the CE1/PRI interface.
[RouterA] display controller e1 4/0/0
E1 4/0/0 current state: UP
Description: HUAWEI, AR Series, E1 4/0/0 Interface
Basic Configuration:
Work Mode is E1 Unframed, Cable type is 120 Ohm balanced.
Frame-format is None, Line Code is Hdb3.
Source Clock is Slave, Data-coding is Normal.
Idle code is 7E, Itf type is 7E, Itf number is 4.
Loopback is Not Set.
Alarm State:
Receiver alarm state is None.
Historical Statistics:
Data in current interval (300 seconds elapsed):
0 Line Code Violations, 0 Path Code Violations
0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
Total Data (last 24 hours):
0 Line Code Violations, 0 Path Code Violations
0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
# Check the status of statistics of the serial interface.
[RouterA] display interface Serial 4/0/0:0
Serial4/0/0:0 current state : UP
Line protocol current state : UP
Description: HUAWEI, AR Series, Serial4/0/0:0 Interface
Route Port, The Maximum Transmit Unit is 1500, Hold timer is 10(sec)
Derived from E1 4/0/0, Unframed mode, the baud rate is 2048000 bps
Internet Address is 10.1.2.1/24
Link layer protocol is PPP
LCP reqsent
Current system time: 2016-11-17 02:06
Last 300 seconds input rate 0 bytes/sec 0 bits/sec 0 packets/sec
Last 300 seconds output rate 2 bytes/sec 16 bits/sec 0 packets/sec
Input: 0 packets, 0 bytes
Total Error: 23397112262, No Buffers: 0
runts: 0, Giants: 0
CRC: 23397112262, Alignments: 20160
Aborts: 0
Output: 326274 packets, 6525480 bytes
Total Error: 0, No Buffers: 0
Giants: 0
Input bandwidth utilization : 0%
Output bandwidth utilization : 0.01%
Configuring Optical Transceivers
Wire Sequence of the E1 Cable (RJ45) | Wire Sequence of the Optical Transceiver Interface |
|---|---|
4 (Rx +) | 1 (Tx +) |
5 (Rx -) | 2 (Tx -) |
1 (Tx +) | 4 (Rx +) |
2 (Tx -) | 5 (Rx -) |
Verification
When the configuration is complete, RouterA and RouterB can communicate with each other.
[RouterA] ping 10.1.2.3
PING 10.1.2.3 data bytes, press CTRL_C to break
Reply from 10.1.2.3: bytes=56 Sequence=1 ttl=125 time=1 ms
Reply from 10.1.2.3: bytes=56 Sequence=2 ttl=125 time=2 ms
Reply from 10.1.2.3: bytes=56 Sequence=3 ttl=125 time=1 ms
Reply from 10.1.2.3: bytes=56 Sequence=4 ttl=125 time=1 ms
Reply from 10.1.2.3: bytes=56 Sequence=5 ttl=125 time=2 ms
--- 10.1.2.3 ping statistics ---
5 packet(s) transmitted
5 packet(s) received
0.00% packet loss
round-trip min/avg/max = 1/1/2 ms
Exception Handling
After cables are connected between the AR and optical transceiver, run the display controller e1 command. The command output shows that the E1 interface is Down, and the IP address of the optical transceiver cannot be pinged on the AR.
To rectify the fault, perform the following steps:
Run the display controller e1 command. If the message "Receiver alarm state is Loss-of-Signal." is displayed under Alarm State, the cables may be disconnected, improperly connected, or in poor contact with the interface. Check the cables and wire sequence.
Check whether cables are properly connected. Cables are properly connected between the AR and optical transceiver.
Check the wire sequence of the cables connected to the AR and optical transceiver.
On the optical transceiver interface connected to the AR, send packets to the AR to conduct a loopback test. The test result shows that the AR interface is Up and the number of packets specified by Input is the same as the number of packets specified by Output on the serial interface. Therefore, the 2E1-M interface card and cables are working properly, and the fault occurs on the optical transceiver.
Conduct a local loopback test on the optical transceiver interface. The test result shows that the optical transceiver interface is Down, indicating that the AR is connected to an incorrect optical transceiver interface. Connect the AR to the correct optical transceiver interface.
That is all I want to share with you!
