Specifications

MBG Engineering Guidelines, Release 8.0

Configure MBG clustering. On the master MBG, go to the “ICPs” tab and add both ICP “A” and ICP “B”. On the

“SIP Trunking” tab, configure a trunk profile for the remote SBC. Add a single routing rule of “*” with ICP “A” and

ICP “B” as the targets of the rule. This configuration will propagate to the secondary MBG.

Incoming calls from the SBC will arrive at either MBG A or MBG B. From there, the MBG will route them to ICP A

if it is up, or to ICP B if ICP A is down. Outgoing calls from either ICP can be routed through either MBG.

5.4 DNS Support

While the ICP can address MBG by its IP address, Mitel recommends the use of a fully-qualified domain name

(FQDN) in the public Domain Name System (DNS) that resolves to the public IP of the MBG server.

Advantage:

• The IP address of the MBG server can be changed, and the ICPs will not need to be reconfigured.

Note: An ICP SIP message will be recognized as being addressed to MBG if the IP in the URI is one that MBG

owns, or the FQDN in the URI either resolves to an IP that MBG owns, or is one of the configured “Allowed

URIs” in the “SIP options” section of the Configuration tab. Typically, the hostnames youadd to the “Allowed

URIs” list will be for the SIP service provider's session border controller or service domain.

Warning: A SIP server requires functional DNS even if ICPs are configured to use IP addresses instead of

FQDNs. MBG is no exception. Failure to provide MBG with a working DNS resolver or preventing MBG

from reaching the Internet DNS root servers can cause delays or failures in call setup.

5.5 Firewall Configuration for SIP Trunking

When MBG is deployed in the DMZ, the corporate firewall protecting the DMZ requires the following rules (in

addition to the common rules found in Firewalls (DMZ deployment)):

Note: Please remember to turn off any UDP flooding protection and any SIP features of the DMZ firewall.

From the Internet to the MBG server:

• allow protocol UDP, destination port 5060 (and return traffic)

From the MBG server to the LAN (or just ICPs):

• allow protocol UDP, destination port 5060 (and return traffic)

Note: This is a minimal configuration. Refer to Appendix A: Firewall Configuration Reference for the full set of

rules and optional settings.