2N Helios IP Configuration Manual page 75

SIP transport protocol – set the SIP communication protocol: UDP (default),
TCP or TLS.
Trusted certificate – specify one of the three sets of certificates issued by
certification authorities to verify the SIP server public certificate validity, refer to
the Certificates subsection. If none is included, the SIP server public certificate is
not verified.
User certificate – specify the user certificate and private key to verify the
intercom authorisation to communicate with the SIP server. There are three sets
of user certificates and private keys, refer to the Certificates subsection.
Local SIP port – set the local port to be used for SIP signalling. The parameter
is not applied until the intercom is restarted. The default value is 5060.
PRACK enabled - enable the PRACK method for reliable confirmation of SIP
messages with codes 101 - 199.
REFER enabled - enable call forwarding via the REFER method.
Send KeepAlive packets – define whether the intercom shall, during a call,
send periodical SIP OPTIONS requests to inquire about the state of the called
station (to detect the station failure, e.g.).
IP address filter enabled – enable the blocking of SIP packet receiving from
addresses other than SIP Proxy and SIP Registrar. The primary purpose of the
function is to enhance communication security and eliminate unauthorised phone
calls.
QoS DSCP value – set the SIP packet priority in the network. The set value is
sent in the TOS (Type of Service) field in the IP packet header. Value is entered
in decimal format. The parameter is not applied until the intercom is restarted.
Starting RTP port – set the starting local RTP port in the range of the length of
60 ports to be used for audio and video transmissions. The default value is 5000
(i.e. the used range is 5060–5059). The parameter is only set for account 1 but
applies to both the SIP accounts.
External IP Address - set the public IP address of the router to which your
intercom is connected. If the intercom IP address is public, leave this field blank.
75
®
2N TELEKOMUNIKACE a.s., www.2n.cz