2N StarGate/BlueTower v5.4 - Manual (Page 78)

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®
frequency of queries routed to the STUN server.
Note
In case the GSM gateway is installed behind the NAT, make
proper routing settings in the NAT router for the relevant ports
(SIP, RTP, STUN). Integrated firewalls can also affect VoIP calls!
Tip
Should you have call troubles (such as unilateral audibility,
connection errors), make sure that all the active elements on
the VoIP call route have been set properly. For easy
troubleshooting, try the point–to–point connection with the
software IP phone (SJ phone, e.g.) in your PC and, at the same
time, apply network analyser tracing (WireShark –
). www.wireshark.org
Refer to the subsection for easy tracing by Others - Utils 2N
®
. StarGate / BlueTower
Tones Generated to VoIP
– generate a ringing tone of your own, or transmit a real Ring tone to VoIP
ringing tone from the GSM/UMTS networks.
ISDN Parameters – General
Use this window to set the PRI ISDN port parameters.
PRI Mode Selection
Here define the PRI 1 (2) ISDN port type.
Synchronisation – define if the gateway will send the synchronisation clock
(MASTER) or receive the synchronisation clock from the connected line (SLAVE).
PRI1 / PRI2
Channel number select – define the way of occupation of B–channels on a
selected ISDN PRI interface. With the UPWARDS selection, the gateway will
occupy the B–channels upwardly (from the selected B–channel number to the
B–channel 32). With the DOWNWARD selection, the gateway will occupy the
B–channels in the descending order (from the selected B–channel number to
B–channel 1).
Preferred channel – select a B–channel.