IMG 2020
On rear panel of the IMG 2020 there are three DS-3 Interfaces. Before configuring the TDM DS-1 objects, each individual DS-3 interface needs to be configured. Depending on whether the IMG 2020 is configured will depend on the number of DS-1's/DS-0's that can be configured. Both T1 DS-3 and E1 DS-3 are supported. To configure, right click on the DS3/Optical Mode object and select New DS-3 Interface. This will create the TDM DS-3 Interface object. Once the DS3 Interface object is created the individual DS1 Spans will need to be configured. Refer to information below.
T1 Protocol on DS3 line (1.544 Mbps)
Supports up to three 672 DS-3 Channels per DS-3 interface (28 DS-1's * 24 DS-0's) = 672 DS-0's
Total = 672 DS-0's per DS-3 * 3 DS-3 Interfaces = 2016 TDM DS-0's
E1 Protocol on DS3 line (2.048 Mbps)
Supports up to three 672 DS-3 Channels (21 DS-1's * 32 DS-0's) = 672 TDM DS-0's
Total = 672 DS-0's per DS-3 * 3 DS-3 Interfaces = 2016 Ports
On the rear of IMG 2020 are four TDM ports. The IMG 2020 supports up to 2016 TDM ports. If the four RJ48 T1/E1 interfaces are going to be utilized, then the number of DS-1's/DS-0's being configured on the signaling port will need to be sacrificed on the DS-3 interfaces. No more than 2016 TDM DS-0's can be configured.
Web GUI Page
Dialogic > IMG 2020 > Facility > DS3/Optical Mode > New DS-3 Interface
Maximum Objects
Three DS-3 Interface objects per DS3/Optical Mode object.
Related Topics and Dependencies
After configuring the DS-3 Interfaces on rear of IMG 2020, each individual TDM DS-1/DS-0 must then be configured. See TDM Span (DS3) topic.
Field Descriptions
Interface ID
The Interface ID field is automatically configured with the next available ID. The Interface ID's change depending on which interface the DS-3 is being created under. See table below.
Interface | ID Range |
DS3 | 0-2 |
Optical (DS3 or Channelized) | 3-5 |
DS-3 Framing Type
The DS-3 Framing formats the method used to multiplex the DS-2 signal into a DS-3 signal. Click in the DS-3 Framing Type field and select the framing format that matches the format of the received signal at the DS-3 network interface on rear of IMG 2020. Choices are below.
M13 - A type of framing that multiplexes the 28 individual DS-1 channels to a DS-3 Channel. M13 is asynchronous. The standard M13 format used widely today cannot provide the maintenance feature end-to-end path parity information.
CBIT (default) - The C-bit parity format redefines the use of the C-bits in the M13 frame making it possible to provide in-service, end-to end path performance monitoring of the DS-3 signal and in-band data links. The ability to monitor degraded seconds, bidirectional end-to-end parity, and far-end alarms gives the C-bit parity format additional maintenance functionality over the M13 format.
Line Length
Set the line length to reflect the physical length of the DS-3 network line. Selections are below
0-225 ft - Select if length of cable is between 0-225 ft (0 - 68.58 meters)
226-450 ft - Select if length of cable is between 226 - 450 ft (68.8 - 137.6 meters)
The next three fields below relate to DS-3 Loopback testing. Loopback testing is used as a diagnostic to troubleshoot connection and signal integrity issues. Refer to the topic for more information on using the fields below.
DS3 and DS1 FEAC Responses (Far End Alarm and Control Channel Responses)
The DS3 and FEAC Responses field can only be modified if the Framing Type is set to C-BIT. Enabling this option allows loop-back to be configured from any far-end equipment connected on the other end of the line. These can be used to send and receive loop up codes and information from the far end T3 device. Either enable or disable this functionality through the drop down menu in this field. FEAC alarms are sent from the remote end device towards the local device by means of the C bit in the Sub-frame. When a failure is declared on the remote end unit this is how it notifies the near end unit. Some FEAC Codes are shown below.
Alarm Codes
Description | Binary Representation |
DS3 Equip. Failure(Service Affecting) | 011001 |
DS3 LOS | 001110 |
DS3 OOF | 000000 |
DS3 AIS RCV | 010110 |
DS3 IDLE RCV | 011010 |
DS3 EQUIP FAIL (NON-SERVICE AFFECT) | 001111 |
COMMON EQUIP. FAIL (NSA) | 011101 |
MULTIPLE DS1 LOS | 010101 |
DS1 EQUIP FAIL | 000101 |
SINGLE DS1 LOS | 011110 |
DS1 EQUIP FAIL (NON-SERVICE AFFECT) | 000011 |
FEAC Codes can be sent to put remote end equipment in loop-back mode. There is a specific FEAC code to request ALL DS1's be put in loop-back. There are also specific FEAC codes for each individual span offset. The local IMG 2020 can request that the far end put all DS1's in loop-back (Send FEAC code to put ALL DS1's in loop-back on remote node). If only one DS1 offset (for example offset 14) needs to be put in loop-back then the local IMG 2020 can send the code value that corresponds to offset 14. This is achieved by setting the starting and ending offset in the DS-1 Spans object to the same value. The DS-1 Span object is configured under the DS3 Interface span. Below are a few codes to accomplish this.
Loopbacks
Description | Binary Representation |
Line loopback activate | 000111 |
Line loopback de-activate | 011100 |
DS3 Line | 011011 |
DS3 Loopback Mode
No Loopback (Default) - Normal Operation
Local Loopback - Loops back the complete DS3 (Including Signaling/Framing) so that a far end piece of equipment can send a test such as a BERT test towards the local IMG 2020.
Remote Loopback (CBIT Only) - The local IMG 2020 sends out a FEAC code to a far end piece of equipment telling it to go into loopback mode (Including Signaling/Framing) so the local IMG 2020 can send out a test such as the BERT test.
DS1 Loopback Mode (ALL)
No Loopback (Default) - Normal Operation
Local Loopback - Loops all of the individual DS-1's within the DS3 but the DS3 framing\signaling is not looped back. DS-1 loop back loops a single DS-1 within the DS-3. (DS-1 Loopback is achieved by setting the Starting and Ending Offset in the DS-1 Span object to the same value. The DS-1 Span object is configured under the DS-3 Interface object).
Remote Loopback (CBIT Only) - The local IMG 2020 sends out a FEAC code to a far end piece of equipment telling it to loop all of the individual DS1s within the DS3 but the DS3 framing\signaling is not looped back.
Following the request to put DS-1 offset 14 in loop-back, you CANNOT make another request for loop-back on another span without first taking span 14 out of loop-back.
Monitoring Fields
DS3 Status - Displays the status of the DS3. (In Service, Out Of Service, Receiving Red, Out Of Frame/Loss of Signal).
DS3 FEBE Status - Indicates a framing or CP bit parity error from the transmitter.
DS3 Local Loopback Status - Displays status of the DS3 local loop-back status.
DS1 Local Loopback Status (ALL) - Displays status of the DS1 local loopback status.
Button Functionality
In Service - If the DS0's are Out Of Service, clicking on the In Service button will attempt to bring then into service.
Out of Service - If the DS0's are In Service, clicking on the Out Of Service button will attempt to bring them Out Of Service
DS1 Loopback Mode within the DS3
Local or Remote Loopback on a DS1 within the DS3 isnt supported. Only DS1 LoopBack Mode (All) is supported.