Configuring an E1 Interface

To configure properties on an E1 interface:

From the Configure Interfaces page, as shown in Figure 1, select the E1 interface you want to configure.
The properties you can configure on an E1 interface are displayed, as shown in Figure 2.
Figure 2: E1 Interfaces Configuration Page
Enter information into the Configure Interfaces page, as described in Table 5.
Click one of the following buttons:
- To apply the configuration and return to the Configure Interfaces page that lists all interfaces, click OK.
- To cancel your entries and return to the Configure Interfaces page, click Cancel.

Table 5: E1 Configuration Summary

Field	Function	Your Action
Logical Interfaces
Add logical interfaces	Defines one or more logical units that you connect to this physical E1 interface. You must define at least one logical unit for an E1 interface. You can define multiple units if the encapsulation type is Frame Relay.	Click Add.
Logical Interface Description	(Optional) Describes the logical interface.	Type a text description of the logical interface to more clearly identify it in monitoring displays.
IPv4 Addresses and Prefixes	Specifies one or more IPv4 addresses for the interface.	Click Add. Type one or more IPv4 addresses and prefixes. For example: 10.10.10.10/24 Click OK.
Physical Interface Description	(Optional) Adds supplementary information about the physical E1 interface.	Type a text description of the E1 interface to more clearly identify it in monitoring displays.
MTU (bytes)	Specifies the maximum transmission unit size for the E1 interface.	Type a value between 256 and 9192 bytes. The default MTU for E1 interfaces is 1504.
Clocking	Specifies the transmit clock source for the E1 line.	From the list, select one of the following: internal—Device's own system clock (the default) external—Clock received from the E1 interface
Per Unit Scheduler	Enables scheduling on logical interfaces. Allows you to configure multiple output queues on a logical interface and associate an output scheduler and shaping rate with the queues.	To enable scheduling, select the check box. To disable scheduling, clear the check box.
Encapsulation
Encapsulation	Specifies the encapsulation type for traffic on the interface.	From the list, select the encapsulation for this E1 interface: PPP Frame Relay Cisco HDLC
Enable CHAP	Enables or disables CHAP authentication on an E1 interface with PPP encapsulation only.	To enable CHAP, select the check box. To disable CHAP, clear the check box.
CHAP Local Identity (available if CHAP is enabled)
Use System Host Name	Specifies that the E1 interface uses the device's system hostname in CHAP challenge and response packets.	To enable, select the check box (the default). To disable, clear the check box.
Local Name	If Use System Host Nameis disabled, specifys the local name for CHAP to use.	Type a local name for this E1 interface.
CHAP Peer Identity	Identifies the client or peer with which the device communicates on this E1 interface.	Type the CHAP client name.
CHAP Secret	Specifies the secret password for CHAP authentication, known to both sides of the connection.	Type a password that is known to the other side of the connection. Use a combination of letters and numbers that is difficult for others to guess.
E1 Options
BERT Algorithm	Specifies the bit error rate test (BERT) algorithm to use during a BERT. BERT is supported only when transmission is unframed. (See the Unframed option.)	From the Bert Algorithm list, select the algorithm to use: all-ones-repeating alternating ones-zeros all-zeros-repeating pseudo-2e11–o152 pseudo-2e15–o151 pseudo-2e20–o151 pseudo-2e20–o153 pseudo-2e23–o151 pseudo-2e29 pseudo-2e31 pseudo-2e9–o153
BERT Error Rate	Specifies the exponent n in the bit error rate 10–n.	Type a value between 3 and 7, or 0. For example, a value of 6 specifies that 1 bit out of 1,000,000 is transmitted in error. The default is 0 (no bits are transmitted in error).
BERT Period	Specifies the length of time, in seconds, of the BERT.	Type a value between 1 and 240. The default is 10.
Frame Checksum	Specifies the number of bits in the frame checksum. A 32-bit checksum provides more reliable packet verification, but is not supported by some older equipment.	Select 16 or 32. The default checksum is 16.
Framing Mode	Specifies the framing mode for the E1 line.	From the list, select one of the following: g704—The default g704–no-crc4—G704 without cyclic redundancy check 4 (CRC4) unframed—Unframed transmission format
Invert Data	Enables or disables data inversion. Data inversion is normally used only in alternate mark inversion (AMI) mode.	To enable, select the check box. To disable, clear the check box.
Loopback	Configures the E1 interface as a loopback interface for testing purposes. When E1 is configured as a local loopback interface, the device transmits test traffic simultaneously to the CSU and to the receiver at the E1 interface. When E1 is configured as a remote loopback interface, test traffic transmitted by the CSU is simultaneously received at the E1 interface and transmitted back to the CSU.	From the Loopback list, select one of the following: local—Traffic loops from the transmitter to the receiver at the E1 interface during tests. remote—Traffic loops from the receiver to the transmitter at the E1 interface during tests.
Timeslots	Specifies the number of time slots allocated to a fractional E1 interface. By default, an E1 interface uses all the time slots.	Type numeric values from 2 through 32. Separate discontinuous entries with commas, and use hyphens to indicate ranges. For example: 2,4,7–9