Yealink SIP-T54S Administrator's Manual page 904

Administrator's Guide for SIP-T2 Series/T19(P) E2/T4 Series/T5 Series/CP860/CP920 IP Phones
Details of Configuration Parameter:
account.X.ptime
Description:
Configures the ptime (in milliseconds) for the codec for account X.
0-Disabled
10-10
20-20
30-30
40-40
50-50
60-60
If it is set to 0 (Disabled), the ptime negotiation is disabled.
X ranges from 1 to 16 (for SIP-T54S/T48G/T48S/T46G/T46S/T29G)
X ranges from 1 to 12 (for SIP-T52S/T42G/T42S)
X ranges from 1 to 6 (for SIP-T41P/T41S/T27P/T27G)
X ranges from 1 to 3 (for SIP-T40P/T40G/T23P/T23G)
X ranges from 1 to 2 (for SIP-T21(P) E2)
X is equal to 1 (for SIP-T19(P) E2/CP860/CP920)
Example:
account.1.ptime = 20
Web User Interface:
Account->Advanced->PTime(ms)
Phone User Interface:
None
To configure the ptime for the account via web user interface:
Click on Account->Advanced.
1.
Select the desired account from the pull-down list of Account.
2.
878
Parameter Permitted Values
0, 10, 20, 30, 40, 50
or 60
Default
20