VoIP
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SonicOS Enhanced 4.0 Administrator Guide
The Additional SIP signaling port (UDP) for transformations setting allows you to specify a
non-standard UDP port used to carry SIP signaling traffic. Normally, SIP signaling traffic is
carried on UDP port 5060. However, a number of commercial VOIP services use different ports,
such as 1560. Using this setting, the security appliance performs SIP transformation on these
non-standard ports.
Tip Vonage’s VoIP service uses UDP port 5061.

Configuring H.323 Transformations

Select Enable H.323 Transformation in the H.323 Settings section and click Apply to allow
stateful H.323 protocol-aware packet content inspection and modification by the SonicWALL
security appliance. The SonicWALL security appliance performs any dynamic IP address and
transport port mapping within the H.323 packets, which is necessary for communication
between H.323 parties in trusted and untrusted networks/zones. Disable the Enable H.323
Transformation to bypass the H.323 specific processing performed by the SonicWALL
security appliance.
Select Only accept incoming calls from Gatekeeper to ensure all incoming calls go through
the Gatekeeper for authentication. The Gatekeeper will refuse calls that fail authentication.
Select Enable LDAP ILS Support to enable Microsoft NetMeeting users to locate and connect
to users for conferencing and collaboration over the Internet.
The H.323 Signaling/Media inactivity time out (seconds) field specifies the amount of time
a call can be idle before the SonicWALL security appliance denying further traffic. A call goes
idle when placed on hold. The default time value for H.323 Signaling/Media inactivity time
out is 300 seconds (5 minutes).
The Default WAN/DMZ Gatekeeper IP Address field has a default value of 0.0.0.0. Enter the
default H.323 Gatekeeper IP address in this field to allow LAN-based H.323 devices to discover
the Gatekeeper using the multicast address 224.0.1.41. If you do not enter an IP address,
multicast discovery messages from LAN-based H.323 devices will go through the configured
multicast handling.
Configuring BWM and QoS
One of the greatest challenges for VoIP is ensuring high speech quality over an IP network. IP
was designed primarily for asynchronous data traffic, which can tolerate delay. VoIP, however,
is very sensitive to delay and packet loss. Managing access and prioritizing traffic are important
requirements for ensuring high-quality, real-time VoIP communications.
SonicWALL’s integrated Bandwidth Management (BWM) and Quality of Service (QoS) features
provide the tools for managing the reliability and quality of your VoIP communications.