IMG 1010 - Configuring T1 or E1 Bearer Profile - 10.5.x

On the rear of the IMG are interfaces that are designated to be configured for TDM spans. There are 28 Bearer interfaces and four Signaling/Timing interfaces. Each interface in considered a span or DS-1. Each Span/DS-1 needs to have a profile associated with it to identify parameters such as Signaling and Framing. The IMG will allow up to 64 T1 and 64 E1 profiles to be configured. How to configure a profile for each span is described below.

Configure TDM Profiles

• Right-click on the IMG EMS object and select New Profiles. A Profiles Object will get created. The Profiles object is a container or parent object and no configuration is needed here.

• Right-click Profiles and select either New T1 Profile or New E1 Profile. A T1 or E1 profile object will get created.

• Use the drop down menus to configure the E1 or T1 profile. Refer to the T1 Profile Pane and E1 Profile Pane sections below for more information on the individual fields in these objects.

T1 Profile Pane

T1 Field Descriptions:

Name

A name entered that describes the profile being created.

Framing

T1 Framing accepts inputs from 24 different sources, converts each individual source into Pulse Coded Modulated bytes and Time Division multiplexes the samples over a four wire facility. The two types of framing are D4 and ESF. Select which framing format will be configured in this T1 profile.

ESF (Default)- The Extended Superframe Format (ESF) extends the D4 superframe from 12 frames to 24 frames. ESF also redefines the 193rd bit location in order to add additional functionality.

D4- The original framing format for T1 was D4 framing. A D4 frame consists of 192 data bits: 24 channels X 8 bits per channel and a single framing bit. D4 defines a 12-bit framing sequence which is sent as the 193rd bit in 12 consecutive frames. These 12 frames together are referred to as a superframe.

Signaling

Clear Channel - Clear Channel (CCS) uses Out-of-Band signaling which is the transmission of signaling on a separate channel from the data/voice. SS7 and ISDN utilize Clear Channel signaling.

CAS- Channel-associated signaling (CAS) is signaling in which control signals, such as those for synchronizing and bounding frames, are carried in the same channels as voice and data signals.

Line Length

The Line Length field specifies the length of the T1 line the T1 DS-1 will be using. The IMG 1010 automatically compensates for loss in decibels based on the distance from the IMG 1010 to the next in the network. Select from drop down menu

In SNMP, the first value in the range is returned, in meters, as shown above 

Line Coding

Line coding involves the manner in which bits are sent as well as providing a means of synchronization. Select the type of line coding to be used from drop down menu.

B8ZS zero suppressing (Default) - B8ZS (Bipolar Eight Zero Suppression) signaling uses frames that are grouped into Extended Super-Frames (ESF). B8ZS with ESF is now the predominant T-carrier system. B8ZS allows a data rate up to 64 kbps and is used in both voice and data.

AMI (Alternate Mark Inversion) - AMI (Alternate Mark Inversion) signaling uses frames grouped into Super-Frames or D4 Framing. D4 framing is an older version of line coding. AMI limits the data rate to 56 kbps and used for inband signaling.

Bit 7 zero suppressing - Bit 7 Zero Suppression the seventh bit is forced to a high or 1. Since the seventh bit is forced to a 1 then the byte becomes unreliable and is used primarily for voice and not data.

For T1 SS7 links with line coding configured for B7ZS, only the 48 Kbps data rates (configured in the IMG 1010 - SS7 Link pane) are valid.

Loopback Mode

Bearer or Signaling DS1’s can be configured for local or remote loopback. Each span offset must be individually configured.

• No Loopback

• Local Loopback

• Remote Loopback
  Note: When you place a span in loopback mode the Span Status will indicate Out Of Service. Following the test you must manually put the span back in service by selecting the In Service button.

See IMG 1010 - DS3 Diagnostics for more information.

E1 Profile Pane

E1 Field Descriptions:

Name

Click in the Name field and enter a name that identifies the E1 DS-1 Profile being created.

Coding Method

Line coding involves the manner in which bits are sent as well as providing a means of synchronization. Select the type of line coding to be used from drop down menu.

HDB3 (Default) - The HDB3  (High Density Bipolar 3) code is a bipolar signaling technique. It is very similar to B8ZS and is based on Alternate Mark Inversion (AMI). HDB3 extends AMI by inserting violation codes whenever there is a run of 4 or more 0's. This and similar (more complex) codes have replaced AMI in modern distribution networks. HDB3 is used in E1.

AMI- AMI (Alternate Mark Inversion) signaling uses frames grouped into Super-Frames or D4 Framing. D4 framing is an older version of line coding. AMI limits the data rate to 56 kbps and is used for inband signaling.

Enable CRC4 (Cyclic Redundancy Check)

Cyclic Redundancy Check 4 is a method that checks for errors in transmitted data on E1 trunk lines. CRC-4 support is required for all network switches in Europe. However, some older switches including private branch exchanges (PBXs) do not support CRC-4.

True  - Enable CRC4 on the span that this E1 Profile will be associated with

False (Default)  - Do not perform any error checking on the span that this E1 Profile will be associated with.

Enable FEBE ( Far End Block errors Count)

FEBE is used to indicate framing or CP bit parity errors from the transmitter. Specify using drop down menu whether FEBE is enabled or disabled by selecting True or False.

Line Impedance

Specifies whether the E1 interface located at the rear of the IMG is 75 ohm or 120 ohm. The Default for ITU is G.703 ITU-T (120 ohm).

Signaling Method

Clear Channel - Clear Channel (CCS) uses Out-of-Band signaling which is the transmission of signaling on a separate channel from the data/voice. SS7 and ISDN utilize Clear Channel signaling.

CAS- Channel-associated signaling (CAS) is signaling in which control signals, such as those for synchronizing and bounding frames, are carried in the same channels as voice and data signals.

Layer 1 Management

Select from drop down menu which type of signaling is needed

E1 Layer 1 Mgmt (Default)- Default Variant used for SS7

Euro-ISDN E1 Layer 1 Mgmt- This variant is adopted by all of the European Countries and is used for ISDN (Europe).

Austel-ISDN E1 Layer 1 Mgmt- Variant issued by Austel in Australia and is used for ISDN (Australian Variant).

Transmit All Zeros

Specifies whether transmit all zeros is enabled or disabled.

False (Default)- Transmit all zeros is disabled.

True- Transmit all zeros. Typically used for troubleshooting.

Default E1 Format

The table below shows the default format for E1 spans. You must enable Clear Channel signaling to use timeslot 16 as a voice channel for out-of-band signaling (for example, an ISDN application).

Clear Channel signaling must be enabled to use timeslot 16 as a D channel in ISDN applications.

For CAS, channel 16 will appear as Out of Service.

• Once an E1 or T1 profile has been created then the profile will need to be associated with a particular span or group of spans. Configure a T1 or E1 span. See IMG 1010 - Configuring T1 or E1 Bearer Spans - 10.5.x or IMG 1010 - Configuring T1 or E1 Signaling Spans - 10.5.x

  • Once the spans have been created then the profiles created can be configured for a specific span or group of spans. See screen capture below
    

    

Next Topic

IMG 1010 - Configuring T1 or E1 Bearer Spans - 10.5.x 

IMG 1010 - Configuring T1 or E1 Signaling Spans - 10.5.x

If configuring DS3 see

IMG 1010 - DS3 Physical Span Configuration - 10.5.x