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Configuring E1 Cards

This chapter covers the following topics:
Introduction to E1
Installing the E1 card
Connecting the MAX TNT E1 line to the WAN
Overview of E1 configuration
Understanding configuration requirements
Making a profile the working profile
Assigning a name to E1 line profiles
Enabling a line
Configuring a back-to-back connection
Specifying the framing
Specifying E1 signaling
Configuring ISDN PRI signaling
Configuring R2 signaling
Configuring DPNSS signaling
Configuring clocking
Configuring the front end E1 transceiver
Configuring channel usage
Assigning phone numbers to switched channels
Configuring trunk groups
Configuring nailed channels
Specifying analog encoding for MAX TNT codecs
Default Call-Route profiles

Introduction to E1

An E1 line supports 32 64-Kbps channels, each of which may be used to transmit and receive data or digitized voice. The line uses framing and signaling to achieve synchronous and reliable transmission. The most common configurations for E1 lines are PRI and unchannelized. (For information about provisioning your E1 line for use with the MAX TNT, see Appendix A, "Provisioning the Switch. ")

ISDN Primary Rate Interface (PRI)

In Europe, an E1/PRI line typically supports 30 B channels and one D channel. But if NFAS signaling is in use, more than one ISDN PRI line on a single card can share a single D channel. PRI configurations are used to receive multiple, simultaneous ISDN calls from analog-modem and digital-services dial-in traffic. Another common use of E1/PRI line is to connect a PBX (Private Branch Exchange) to a central office switch.

Nailed or unchannelized E1

An unchannelized E1 line may be used for nailed connections such as to a Frame Relay network. In such cases the configuration is static, and the MAX TNT treats the E1 line as if it were a single connection at a fixed speed, without individual channels.

Typically, when you pay your telephone company for a leased (nailed) line, you pay more for higher bandwidth. Anything in the range of 0bps to 2.048Mbps may be delivered on an E1 line, and provisioned at some 64K fraction of the full E1 bandwidth.

Installing the E1 card

You install E1 cards in the same way you install other MAX TNT slot cards. For instructions, see Installing a slot card.

Connecting the MAX TNT E1 line to the WAN

When connecting your E1 line, keep the following points in mind:

Connect the MAX TNT port either directly to the E1 line or through other network interface equipment. See Figure 8-1 illustration for an example.

Figure 8-1. Connecting your E1 line

Inform your service provider that the equipment is connected, so they can bring up the line.

Monitoring the E1 line with bantam jacks

Each E1 card provides transmit and receive bantam jacks to monitor the status of the E1 lines. The Tx line carries what the MAX TNT transmits to the network. The Rx line carries what the MAX TNT receives from the network. The bantam jacks do not interfere with the signal either coming into or going out of the MAX TNT.

To monitor the E1 lines:

  1. Select the line to monitor by setting the select switch on the E1 card.

  2. Plug in bantam jacks.

Overview of E1 configuration

Table 8-1 lists the sections describing common tasks you might have to perform to configure an E1 line. The table includes a brief description of each task, and lists the parameters you will use.

For complete information about the associated parameters, see the MAX TNT Reference Guide.

Table 8-1. E1 line configuration tasks

Task

Description

Associated parameters
Understanding configuration requirements.

 Before configuring your E1 line, gather the necessary information from your E1 service provider.

 N/A

Making a profile the working profile.

 Before you can edit a profile, you must make it the working profile.

N/A

Assigning a name to E1 line profiles.

Assign a name to the E1 profile.

Name

Enabling a line.

Make a line available for use.

 Enabled

Configuring a back-to-back connection.

 A back-to-back connection lets you connect two MAX TNT units to one another over a crossover E1 cable.

 Back-to-Back

Specifying the framing.

Framing specifies how the bits are sent on the line.

 Frame-Type

Specifying E1 signaling.

 Specify the type of signaling used for your E1 line.

Signaling-Mode

Configuring ISDN PRI signaling.

You must specify the type of network switch providing ISDN service on an E1 PRI line.

 Switch-Type

Configuring R2 signaling.

 Specify R2 signaling and specify R2-specific configuration options.

Signaling-Mode

Number-Complete

Group-B-Signal

Group-II-Signal

Answer-Delay

Configuring DPNSS signaling.

 Specify DPNSS signaling and associated options.

Signaling-Mode

Layer3-End

Layer2-End

NL-Value

Loop-Avoidance

Configuring clocking.

Set Clock-Source to specify whether the E1 line can be used as the master clock source for synchronous connections.

Also specify the priority of the E1 lines to be used for clocking.

Clock-Source

Clock-Priority

Configuring the front end E1 transceiver.

 Set the front end type of the E1 transceiver to Long-Haul or Short-Haul, depending on the type of termination your line uses.

Front-End-Type

Configuring channel usage

 Specify how each of the E1 channels are to be used.

Channel-Usage

Assigning phone numbers to switched channels

Typically, you need specify only the rightmost digits needed to distinguish one number from another. These are called add-on numbers.

Phone-Number

Configuring trunk groups

A trunk group is a group of channels that has been assigned a number.

Trunk-Group

Configuring nailed channels

 You must assign a nailed channel to a group to make it available for use. The group number can be referenced in a Connection or Frame-Relay profile to specify a permanent leased connection using that group of nailed channels.

 Nailed-Group

Chapter 15, "Call Routing in the MAX TNT."

Set up call routing, which the MAX TNT uses to determine where to route incoming and outgoing calls. This information is deprecated in the MAX TNT. The preferred way to set up call-routing is to put all call-routing information in one place: a Call-Route profile.

If you do not use Call-Route profiles, specify the physical address of a device to which calls received on this channel should be routed.

Default-Call-Type

Call-by-Call-Service

Shelf

Slot

Item

Understanding configuration requirements

You need the following information from your E1/PRI service provider:

Note: The MAX TNT cannot receive multichannel calls using MP encapsulation unless all channels of the call share a common phone number (namely, a hunt group). You can request that your service provider supply you with a hunt group.

Making a profile the working profile

When the MAX TNT system detects that E1 card has been installed, it creates a default E1 profile for each of the eight lines on the card.

In the following display example, the Dir command shows eight default E1 profiles created for a card installed in slot 2:

By default, a line is not enabled, which means that it is not available for use. Its default signaling method is inband, typically used for channelized connections.

To configure an E1 profile, make it the working profile by reading it into the edit buffer. For example:

Once you have read in a profile, it remains the working profile until you read in another profile.

To save your configuration changes, use the write command. For example,

To list the parameters in an E1 profile, use the List command, as in the following example:

The following example shows the parameters in an E1 profile, with sample settings:

Assigning a name to E1 line profiles

In an E1 profile, the Name parameter enables you to assign the profile a name. The name can include up to 16 characters. After you assign it, it is displayed after the line's physical address in the Dir command output. For example:

For E1 lines, the Line Status window displays either the name (if assigned) or the physical address. If the name is longer than eight characters, the last character displayed is a plus-sign (+).

Enabling a line

By default each E1 line is disabled. To enable an E1 line, read its profile to make it the working profile, then set enable to Yes, as in the following example:

Configuring a back-to-back connection

For diagnostics, you can configure DASS-2 or DPNSS lines in a back-to-back connection. A crossover cable connects an E1 port of one MAX TNT to an E1 port of another MAX TNT. No switch is required, and the connection is entirely local. One MAX TNT should be set up for DTE operation, and the other for DCE operation.

To specify a back-to-back connection, set the Back-to-Back parameter:

admin> set line back-to-back = [true|false]
admin> write

Specifying the framing

The E1 framing mode may be the G703 (the standard framing mode used by most E1 ISDN and DASS2 providers), 2DS (a variant of G.703 required by most E1 DPNSS providers in the U.K). If the line is not configured for ISDN signaling, you can use the D4 format, also known as the superframe.

Your E1 service provider must provide the correct framing values for your lines.

To specify the framing, set the Frame-Type parameter:

Specifying E1 signaling

An E1 line's signaling mode can be any of the following:

In the E1 profile, configure E1 signaling as follows:

Configuring ISDN PRI signaling

For ISDN signaling you must also specify the type of switch providing E1/PRI service to your MAX TNT. Obtain the information from your ISDN carrier.

When you set the signaling mode to ISDN, you must also set channel 17 as the D channel. Note that ISDN signaling often requires ESF framing and B8ZS encoding.

Configure ISDN PRI service as follows:

To see a complete list of switch types supported on the MAX TNT, refer to the MAX TNT online help or the MAX TNT Reference Guide.

Configuring R2 signaling

R2 signaling is an ITU-T standardized signaling protocol, which can be used on E1 digital trunks for switched circuits. It uses a combination of A/B bit manipulation, in channel 16 of the E1 frame (line signaling), and in-band MF tone generation and detection (register signaling). The relevant specifications are in ITU-T recommendations Q.400 to Q.490. R2 signaling is widely implemented in international markets where ISDN PRI is not yet available. The default bandwidth for data calls coming in over E1 channels using R2 signaling is 64K.

Lines configured for R2 signaling have a number of different options you can set, including:

To configure the line for R2 signaling, proceed as in the following example:

Configuring DPNSS signaling

When you are connecting to a DASS 2 or DPNSS switch, you must set the following parameters:

Contact the carrier for more details. (These settings are not required for ISDN signaling.)

In the following example, an administrator configures DPNSS signaling using a Mercury switch (a variant of DPNSS). The 2DS framing mode is specified-this mode gives a variant of G.703 required by most E1 DPNSS providers in the U.K. To configure an E1 line for DPNSS signaling, proceed as in the following example:

Configuring clocking

You can configure the MAX TNT to use any of the E1 lines as a master clock source for synchronous connections for an entire multishelf system. In synchronous transmission, both the sending device and the receiving device must maintain synchronization in order to determine where one block of data ends and the next begins.

From the E1 lines configured as eligible clock sources, the MAX TNT chooses a clock source on the basis of priority. If multiple E1 lines are configured as eligible clock sources and have an equal clock-priority, MAX TNT chooses one of them at random. Once chosen as the clock source, the line is used until it becomes unavailable or a higher priority source becomes available.

If there are no eligible external sources, the system uses an internal clock generated from the master shelf controller. Using the internal clock is generally not recommended.

The Clock-Source diagnostic command displays the current master clock source. If you execute the command on the shelf controller, it tells which slot (if any) is being used as the clock source. If you execute it on an E1 card, it tells which line is used.

To specify a clock source and set a priority, proceed as follows after reading in the line's E1 profile:

Configuring the front end E1 transceiver

The front-end type of the E1 transceiver may be short haul or long haul. Long haul is only for lines using 120 Ohm termination.

To specify front end settings, proceed as follows after reading in the line's E1 profile

Configuring channel usage

You must specify how each of the 32 channels of an E1 line is to be used. By default, E1 channels are configured as switched. Each of the 32 channels of an E1 line may be configured for one of the following uses:

To specify the channel usage:

  1. List the Line-Interface parameters:

  2. Set the Channel-Usage parameter for the first channel:

Assigning phone numbers to switched channels

Assigning phone number to switched E1 channels is no different that assigning them to switched T1 channels. See Assigning phone numbers to switched channels.

Configuring trunk groups

Like nailed channels that have been assigned a group number, switched channels in a trunk group can be referenced from a Connection profile and Call-Route profile to direct outbound calls to use that specific bandwidth. Trunk groups also serve a variety of other purposes, such as separating lines supplied by different carriers so those lines can be used as backup for each other if one switch becomes unavailable. The decision to use trunk groups is a global one. Once you have enabled the use of trunk groups, every switched channels must be assigned a trunk group number or it will not be available for outbound calls.

Trunk groups limit the number of channels available to multichannel calls, because only channels within the same trunk group can be aggregated.

To enable trunk groups, open the System profile and set use-trunk-groups to Yes, as in the following example:

Then assign the channels of each E1 line to a trunk group, as in the following example:

Note: Command history is very useful for repeating commands. Press the Up-Arrow key to redisplay the command, and then press Enter. (For more information, see The Ascend Command Line Interface.)

Configuring nailed channels

The number of nailed channels must be the same at both ends of the connection. For example, if there are 5 nailed channels at the local end, there must be 5 nailed channels at the remote end. However, channel assignments do not have to match. For example, Channel 1 may be switched at the local end and nailed at the remote end. Channels in a nailed group must be contiguous on the E1 line.

When you configure Connection profiles to use the leased connection, you must specify the Nailed-Group number in the Telco-Options subprofile.

To configure a nailed channel, proceed as in the following example:

Specifying analog encoding for MAX TNT codecs

Codecs connected to T1 use a different encoding standard for digitized analog data than codecs connected to E1. The default for T1 is U-Law, the default for E1 is A-Law.

To specify the analog encoding, proceed as in the following example:

  1. Open the System profile:

  2. Specify the analog encoding for all the codecs in the MAX TNT:

  3. Write the System profile to save the changes: 

SYSTEM written

Default Call-Route profiles

When the MAX TNT system detects that an E1 card has been installed, it creates one default Call-Route profile associated with the card. For example:

This default Call-Route profile routes outbound trunk calls to any line on the card. To handle inbound modem and LAN-session traffic, you should configure specific call routes. For details, see Chapter 15, "Call Routing in the MAX TNT."


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