Altigen AltiWare ACC 5.2, Administration Manual

Page: 304 / 399

Chapter 24: Network Configuration Guidelines for VoIP
292
AltiWare ACC 5.2 Administration Manual
•
The Jitter Buffer should be adjusted according to the bandwidth allocated to data
traffic. For example, a long Ethernet packet (approximately 1500 bytes) traversing
through a WAN which is allocated with 256 kbps of data traffic bandwidth will take
about 50 milliseconds. The Jitter Buffer value should be set to this WAN link
transmission delay plus the typical network jitter delay. To configure the Jitter
Buffer, in AltiEnterprise Manager (
VoIP > Enterprise Network Management )
click the Codec button.
•
If you have heavier data applications running concurrently, the bandwidth reserved
for data traffic should be increased.
•
If your router supports multilink or TCP fragmentation, configure your WAN router
to user smaller packet sizes, for example, 500 bytes.
WAN Router Configuration
The router that connects your LAN and the WAN should support priority queuing.
Configure the router so that the IP/UDP packets being sent to and from an IP station
have higher priority than the packets generated by other stations on the same network.
Consult your router manufacturer for more information on setting up this configuration.
Firewall Configuration
Please note the following important guidelines when working with a firewall on your
network:
•
If a firewall is used to protect your network access security, reconfigure the firewall
to open up TCP and UDP ports to the IP system’s IP address. The relevant ports are
listed in Appendix C “Network Ports” on page 371. This allows IP’s voice and H.323
packets to pass through the firewall freely. If the firewall supports H.323 protocol,
configure the firewall using H.323 instead of opening up the specific ports.
•
Ensure that the rules to permit IP’s H.323 traffic are at the beginning of your access
filter list. This will minimize the delay of latency-sensitive voice packets. This is
especially important with long access lists and/or slow routers.
Network Using NAT
If you plan to connect to your AltiServ system via the Internet and your router or
Internet access provider is using Network Address Translation (NAT), please note that
most NAT implementations DO NOT support H.323.
•
You are probably using NAT if both of the following conditions apply:
–
Your AltiContact Center server's IP address matches any of the following numbers
(where x is any number from 0-255):
•
10.x.x.x
•
172.16.x.x to 172.32.x.x
•
192.168.x.x
–
You are able to connect to the Internet directly without using a proxy server.
•
Contact your router/firewall vendor to obtain a software update for your networking
equipment, or obtain routable address space from your Internet provider. If you are
unsure whether or not you are using NAT, contact your router/firewall vendor or
Internet provider.