Siemens Gigaset A580IP Manual page 132

Area Listen ports for VoIP connections
Use random ports
Click No if you want the phone to use the ports specified in the fields SIP port and
RTP port.
Click Yes if you do not want the phone to use fixed ports for SIP port and RTP port,
but rather to use any free ports from predefined ranges of port numbers.
The use of random ports makes sense if you want several phones to be operated on
the same router with NAT. The phones must then use different ports so that the
router's NAT is only able to forward incoming calls and voice data to one (the
intended) phone.
Use random ports = No
SIP port Specify the port number for the SIP port. Enter a number between 1024 and 49152
in the field.
The default port number for SIP signaling is 5060.
The port number specified must not be in the RTP port number range.
RTP port Specify a range of port numbers that are to be used as RTP ports. This range must
be used in the LAN (router) for the phone.
Enter the lowest port number in the left-hand field and the highest number in the
right-hand field (numbers between 1024 and 55000).
Size of the port number range:
The difference between the port numbers must be at least 6 if you permit two
simultaneous VoIP calls on your phone. The difference must be at least 4 if you only
permit one VoIP call (
The lower of the port numbers in the range (in the left-hand field) must be an even
number. If you enter an odd number, the next lower even number will be selected
automatically (e.g. if you enter 5003, then 5002 is set automatically).
The default port number for voice transmission is 5004.
Use random ports = Yes
SIP port Enter the port number range from which the SIP port is to be selected.
Specify the lowest port number in the left-hand field and the highest number in the
right-hand field (number between 1024 and 49152).
This port number range must not overlap the range specified for RTP port.
The default range is 5060 to 5076.
RTP port Specify a range of port numbers from which the RTP ports are to be selected.
Specify the lowest port number in the range in the left-hand field and the highest
number in the right-hand field.
The default range is 5004 to 5020.
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Select Set to save your settings.
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Allow 1 VoIP call only
Setting the phone with the PC
option on Page 118).
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