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COMfortel 1400 IP/2600 IP/3600 IP - Firmware V2.6 - Operation/Configuration - V05 09/2016
Settings
Providers and PBXs
Keep alive maintains the connection between client and server by sending
NAT keep alive packets which prevent the interruption of the connection. An
intveral for the sending of those NAT keep alive packets must be deter-
mined. This interval indicates after how many seconds NAT keep alive
packets are send to maintain the NAT mapping in the firewall.
NAT keep alive is enabled and an additional entry must be made:
NAT keep alive interval (sec.) (15...255)
Enter NAT keep alive interval.
Note:
Some providers lock accounts if the
NAT keep alive interval
is
too short. As a rule, this is reported with error message 503 during SIP
registration. If this problem occurs, we recommend you reduce the value
(e.g. to 180).
RTP
Codecs
A codec is a method that encodes (digitises) analogue voice data for trans-
mission and again decodes again, meaning converts into back into voice.
There are various codecs that feature different voice data compression
rates thereby require different band widths for data transmission. The
equality of VoIP calls is dependent on the codec used.