Configuring T1 Framing and Coding - Springware
Description:
If coding on Dialogic T1’s are not configured to match the PBX, Dialogic could fail to start. By default, when selecting "None" (robbed-bit), coding is set to AMI and framing is set to D4. This tech note will explain how to change coding and framing when using Springware T1 cards, and how to avoid start up problems.
Symptom:
By default, when selecting "None" (robbed-bit), in DCM (under the “Interface” Tab), coding and framing is set to AMI, D4. If a T1 from a PBX or Central Office is connected to the Dialogic cards before either side is configured, it could cause Dialogic to fail start-up if there is a coding mismatch (e.g. Dialogic set to AMI, PBX set to B8ZS). The problem is more noticeable if there are errors or noise on the line. If only a few channels have errors or noise, Dialogic may fail at startdrv.exe. If all channels have errors and noise, Dialogic may fail at genload.exe (one or more boards may fail to download).
Reason for the problem:
Dialogic fails to start because the control processor gets flooded with interrupts from the PMC framer chip due to incorrect configuration. If a user plugs in a T1 from a PBX or C.O. configured for B8ZS, that has noise or excessive errors, into a Dialogic Springware T1 board (D240/480JCT) that is configured for defaults, (AMI, D4...NONE for ISDN), it's possible that Dialogic will not start. It has been noticed that the more channels that have errors and noise, the quicker Dialogic will fail to start. If the entire T1 is in this state, it's possible that boards will fail to download (genload.exe fails), and Dialogic will not start. If there are fewer channels in this state, Dialogic may pass genload (firmware actually downloads to the installed boards) but may fail to start devices (startdrv.exe fails). Dialogic service will then fail to start.
Fix / Solution:
The problem is resolved by a .prm file change / selection. The following can be done in order to ensure the problem does not occur.
1. Make sure that the coding on the T1 from the PBX or C.O. is configured to match the Dialogic Springware board defaults (AMI, D4) before connecting it to a Dialogic board. This configuration should be done by the actual PBX administrator / Central Office.
2. Make sure that Dialogic's framing and coding is properly configured to match the PBX. If the coding and framing of the PBX / C.O. is already configured or can’t be changed, coding and framing can be changed on the Dialogic side. By default, Dialogic is set to AMI (No zero code suppression 00), D4 (00). You can change it to B8ZS by doing the following:
Coding:
a. Modifying the Zero Code Suppression Mode parameter (0020) to B8Zs, in the corresponding country specific parameter file (Specified in DCM under the “Country” tab). (Example: for United States D240JCT or D480JCT, you can modify the US_240.prm file in Dialogic\data). Un-comment 0020 and make the following change:
;--- ZERO CODE SUPPRESSION MODE (Parameter type 20H)
;--- Sets the Zero Code Suppression mode for T1
;--- Possible values for the data are as follows:
;--- 00H = No zero code suppression.
;--- 01H = B8ZS.
;--- 02H = Bit 7 jamming.
;--- The default data value is 00H (no zero code suppression)
0020 01
OR:
b. Modifying the Zero Code Suppression Mode parameter (0020) in the spandti.prm file (Dialogic\data).
;--- ZERO CODE SUPPRESSION MODE (Parameter type 20H)
;--- Sets the Zero Code Suppression mode for T1
;--- Possible values for the data are as follows:
;--- 00H = No zero code suppression.
;--- 01H = B8ZS.
;--- 02H = Bit 7 jamming.
;--- The default data value is 00H (no zero code suppression)
0020 01
NOTE: In order for this to take affect, the spandti.prm file has to be read into DCM. This can be done by clicking on the “Misc” tab, Clicking on “ParameterFile”, and entering “spandti.prm” in the “Value” drop down box.
3. Framing for Dialogic T1 by default is set to D4 (00). In order to change framing to ESF for Dialogic Springware T1, the following must be done:
Framing:
a. Modify the Protocol Type parameter in the
spandti.prm file. In order for this to take affect, the
spandti.prm file has to be read into DCM. This can be done by clicking on the “Misc” tab, Clicking on “ParameterFile”, and entering “spandti.prm” in the “Value” drop down box.
;--- FRAMING FORMAT (Parameter type 14H)
;--- Defines the T1 framing format.
;--- Possible values for the data are as follows:
;--- 00H = D4 framing.
;--- 01H = ESF framing.
;--- The default data value is 00H (D4 framing).
0014 00
b. In order for this to take affect, the spandti.prm file has to be read into DCM. This can be done by clicking on the “Misc” tab, Clicking on “ParameterFile”, and entering “spandti.prm” in the “Value” drop down box.
Note: You can find out what .prm files are are being "read in" by Dialogic by running the following command from a command prompt (Dialogic Service must be stopped). After genload - dt2 is finished running, look for the .prm files mentioned during this process by looking back up through the window (highlighted in red).
c:\> genload -dt2
Example:
Parameter download (1 21 11 31 ) 1(04112).
Board 1: finished parameter file C:\PROGRAM FILES\DIALOGIC\DATA\VOICE.PRM - 539
lines read
Board 1: finished parameter file C:\PROGRAM FILES\DIALOGIC\DATA\US_240.PRM - 167
lines read 21(04514).
Board 21: finished parameter file C:\PROGRAM FILES\DIALOGIC\DATA\VOICE.PRM - 539
lines read
Board 21: finished parameter file C:\PROGRAM FILES\DIALOGIC\DATA\US_240.PRM - 16
7 lines read 11(04112).
Board 11: finished parameter file C:\PROGRAM FILES\DIALOGIC\DATA\VOICE.PRM - 539
lines read
Board 11: finished parameter file C:\PROGRAM FILES\DIALOGIC\DATA\US_240.PRM - 16
7 lines read 31(04514).
Board 31: finished parameter file C:\PROGRAM FILES\DIALOGIC\DATA\VOICE.PRM - 539
lines read
Board 31: finished parameter file C:\PROGRAM FILES\DIALOGIC\DATA\US_240.PRM - 16
7 lines read
Starting firmware (1 21 11 31 ) 1:Ack 21:Ack 11:Ack 31:Ack
Delay ...
Firmware started (1 21 11 31 ) 1r 21r 11r 31r 1 21 11 31
Fourth pass
First Redownload pass
Second Redownload pass
Outputting Configuration data
4 records written to DIALOGIC.INF file
Closing DIALOGIC.INF file
Closing voxcfg file
Closing dticfg file
Closing vector list file
D/480JCT-2T1 (PCI ID 1) Download .. SPANPLUS Firmware Version 6.65 Build 0242
1 Intel« Dialogic« Board Successfully Installed
First published: 06-Apr-2008
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