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.
E1 Interface Card
All the timeslots, except timeslot 0, on E1 interfaces of an E1 interface card are randomly bundled into multiple channel sets. Each channel set corresponds to a channel. The AR supports E1 interface cards and configuration of CE1/PRI interfaces.
Table E1 interface cards supported by the AR lists the five types of E1 interface cards supported by the AR. Users can choose appropriate E1 interface cards based on the number of interfaces that are required and the connectors that are used.
Interface Card | Number of Interfaces Supported | Connector Type | Slot Type | Working Mode |
1E1/T1-M | 1 | D89 | SIC slot | e1-data/t1-data |
2E1/T1-M | 2 | D89 | SIC slot | e1-data/t1-data |
2E1/T1-M-W | 2 | D89 | WSIC or XSIC slot | e1-data/t1-data |
4E1/T1-M | 4 | RJ45 | e1-data | |
8E1/T1-M | 8 | RJ45 | e1-data |
E1 Cable
Users can select E1 cables based on the type of E1 interface cards and the type of connectors connected to E1 interfaces. Table E1 cables supported by the AR lists the E1 cables supported by the AR.
Cable | Interface Card | Working Mode of the Interface Card |
75-ohm DB9-to-BNC cable | 1E1/T1-M 2E1/T1-M 2E1/T1-M-W | e1-data |
75-ohm RJ45-to-BNC cable | 4E1/T1-M 8E1/T1-M | e1-data |
120-ohm DB9-to-RJ45 cable | 1E1/T1-M 2E1/T1-M 2E1/T1-M-W | e1-data |
120-ohm RJ45-to-RJ45 cable | 4E1/T1-M 8E1/T1-M | e1-data |
100-ohm DB9-to-RJ45 cable | 1E1/T1-M 2E1/T1-M 2E1/T1-M-W | t1-data |
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 Connecting to a transmission network through an E1 leased line, 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.
Figure1 Connecting to a transmission network through an E1 leased line
