Snom 320 - Manual (Page 92)

92 • Settings
[ S N O M 3 2 0 M A N U A L V 1 . 0 0 ]
Dynamic RTP port start, Dynamic RTP port stop: If you want to
set up the port range out of which the RTP ports will be dynamically taken,
specify the start port and end port number, respectively, in these fi elds.
Type of Service (TOS): You can set up the TOS value in this fi eld,
for example, 160 in the above screenshot. This option enables the phone
to support quality of service (QOS) in a network, if all of the involved
network parts also support QOS.
DTMF Payload Type: Set up the payload type for Out-of-Band
DTMF here The default setting is 101. This can be an arbitrary 8-bit value
as long as the involved communication partners are both using the same
value.
Network identity (port): Set a static local port number, which is
used for the SIP protocol communication, in this fi eld. Usually, the phone
chooses a random one!
SIP T1 (ms): Set the retry timer in milliseconds after which an
unanswered request is resent. If it is set to 500, the phone will resend
the unanswered request after 500, 1000, 2000, 4000, 6000…31500 ms.
If the request is still unanswered after this procedure, an error message
will be shown on the display.
SIP Session Timer (s): Specify the session timer for SIP in seconds
in this fi eld. For instance, a Re-INVITE will be sent after its expiration.
Dirty Host TTL (s): Specify the “Time to Live” (TTL) for dirty
hosts in seconds. This means that, when a phone was unable to reach a
host, the phone will not try to reach this host again until the time specifi ed
in this fi eld has elapsed.
SIP Max Forwards: If you set a maximum number of forwards
in this fi eld, each time a forward is sent the counter is reduced by one.
When zero is reached, the forwarding will stop. This prevents the phone
from running into a SIP message-forwarding loop.
ENUM Suffi x: When using ENUM, you can specify a service suffi x
here, if desired. There is more than one service that supports ENUM
lookups, and you can select here which one you want to use. Leave the
default value e164.arpa if you don’t know.
Use user=phone: Turn this setting on if you want to use
user=phone in SIP URIs. This is to distinguish phones from different non-
phone devices like gateways, etc. (RFC2543 deprecated).
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