User's Manual
Avaya Branch Gateway Manager 10.0 Page 147
15-601011 Issue 29r (Friday, November 02, 2012)B5800 Branch Gateway
Configuration Settings: System
5.3.2.2 VoIP
This form is used to set the system defaults for VoIP operation on the LAN interface.
Usability
· Mergeable: These settings are not mergeable. Changes to these settings will require a reboot of the system.
Configuration Settings
· H.323 Gatekeeper Enable: Default = On
This settings enables gatekeeper operation.
· SIP Trunks Enable: Default = On
This settings enables support of SIP trunks.
· SIP Registrar Enable: Default = On.
This setting enables support for SIP extensions. When selected, the SIP Endpoints tab if visible.
· RTP Port Number Range:
For each VoIP call, a receive port for incoming Real Time Protocol (RTP) traffic is selected from a defined range of
possible ports, using the even numbers in that range. The Real Time Control Protocol (RTCP) traffic for the same call
uses the RTP port number plus 1, that is the odd numbers. For control units and Avaya H.323 IP phones, the default
port range used is 49152 to 53246. On some installations, it may be a requirement to change or restrict the port range
used. It is recommended that only port numbers between 49152 and 65535 are used, that being the range defined by
the Internet Assigned Numbers Authority (IANA) for dynamic usage.
· !Important
The minimum and maximum settings of the port range should only be adjusted after careful consideration of the
customer network configuration and existing port usage. For pre-Release 6.x systems, the gap between the
minimum and maximum port values must be at least 1024. For Release 6.x and higher, the gap between the
minimum and maximum port values must be at least 254.
· Port Range (minimum): Default = 49152. Pre-6.x: Range = 1024 to 64510/6.x+: 1024 to 65280.
This sets the lower limit for the RTP port numbers used by the system.
· Port Range (maximum): Default = 53246. Pre-6.x: Range = 2048 to 65534/6.x+: 1278 to 65534.
This sets the upper limit for the RTP port numbers used by the system. Enable RTCP Monitor On Port 5005:
Default = On.
For 1600, 4600, 5600 and 9600 Series H.323 phones, the system can collect VoIP QoS (Quality of Service) data
from the phones. For other phones, including non-IP phones, it can collect QoS data for calls if they use a VCM
channel. The QoS data collected by the system is displayed by the System Status Application.
· This setting is mergeable. However it only affects H.323 phones when the register with the system. therefore any
change to this setting requires H.323 phones that have already been registered to be rebooted. Avaya H.323
phones can be remotely rebooted using the System Status Application.
· The QoS data collected includes: RTP IP Address, Codec, Connection Type, Round Trip Delay, Receive Jitter,
Receive Packet Loss.
· This setting is not the same as the RTCPMON option within Avaya H.323 phone settings. The system does not
support the RTCPMON option.
· DiffServ Settings
When transporting voice over low speed links it is possible for normal data packets (1500 byte packets) to prevent or
delay voice packets (typically 67 or 31 bytes) from getting across the link. This can cause unacceptable speech quality.
Therefore it is important that all traffic routers and switches in a network to have some form of Quality of Service
mechanism (QoS). QoS routers are essential to ensure low speech latency and to maintain sufficient audible quality.
· The system applies the DiffServ settings to outgoing traffic on any SIP lines which have their User Network
Topology Info setting (Line | Transport ) set to match the LAN interface. DiffServ settings are not applied
to any other traffic on the systems LAN interface.
· The system does not use DiffServ markings used to prioritize traffic on its LAN interface.
· The system supports the DiffServ (RFC2474) QoS mechanism. This uses a Type of Service (ToS) field in the IP
packet header. The system uses this field to prioritize voice and voice signaling packets on its WAN interfaces.
Note that the system does not perform QoS for its Ethernet ports.
· The hex and decimal entry fields for the following values are linked, the hex value being equal to the decimal
multiplied by 4.
· DSCP (Hex): Default = B8 (Hex)/46 (decimal). Range = 00 to FC (Hex)/0 to 63 (decimal)
The DiffServ Code Point (DSCP) setting applied to VoIP calls. For correct operation, especially over WAN links, the
same value should be set at both ends.
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