Highrate recovery packets, Cf show ims.media.codec.t38

Parameter

jbig

Ecm

extended_ roundtrip

data_wait_time

low_rate_ recovery_ packets

high_rate_ recovery_ packets

Description

JBIG should be used, (reduces bandwidth). (TrueFalse)

Specifies if ECM should be used or not. (TrueFalse)

Enables the support of dealing with extended round trip delays (TrueFalse)

This parameter indicates the time for internal buffering appropriate V.21, ECM and non-ECM page data in the case if the end of line or the end of the HDLC frame is not detected. The value range is from 0 up to 100. The default value is to set to 50 which is of 500 ms buffering. One unit is of 10 ms. After the Data Wait Time T.38 starts with the modulation also if not all data is received

This parameter is used for the Redundancy and the FEC error Correction Mode on a UDP transmission for V.21. The parameter indicates the number of additional recovery data packets send during a low rate Fax transmission (control data). The value can be between 0 and 4.

This parameter is used for the Redundancy and the FEC error Correction Mode on a UDP transmission for V.17, V.29, and V.27. The parameter indicates the number of additional recovery data packets send during a high rate Fax transmission (image data). The value can be between 0 and 4.

To show the current configuration for T.38, use the following command:

cf show ims.media.codec.t38

ims.media.codec.t38.forward_error_correction false

.max_bit_rate 14400

.local_tcf false

.fill_bit_removal false

.transcoding_mmr false

.transcoding_jbig false

.ecm true

.extended_roundtrip false

.data_wait_time 500

.low_rate_recovery_packets 4

.high_rate_recovery_packets 1

Depending on radio network characteristics, there might be a need for fine tuning T.38.

ECM (Error Correction Mode) may need to be reconfigured since ECM is sensitive for packet loss, it might be necessary to disable this.

2/221 02-FGB 101 327 Uen B – November 2007