Resiliency
As an example, in an SCN configuration of System A and System B where the centralized voicemail is connected to System B, and a number of IP phones are connected to either System A or System B. If System B fails then:
System A will automatically take over from System B and support IP phones, hunt groups, and DHCP if required.
Voicemail Pro will reregister to System A.
For users in an SCN, when they hot desk to another IP Office system, they retain their licensed profile setting as configured on their home system.
All System B users' personal contacts and call logs will continue to be available (96x1, 9600, and 1600 phones).
For multisite networks, VCM modules are required in all systems being connected. The IP lines may be configured in a start or a meshed configuration. One of the advantages of a meshed configuration is that it removes the risk of a single point of failure within the network. Also the names and numbers (groups, line, services, etc.) on the separate IP Office systems should be unique to reduce potential maintenance confusion.
EachIP Office system broadcasts UDP messages on Port 50795. These broadcasts typically recur every 30 seconds but BLF updates are potentially more frequent. There are no updates if there is no activity and the overall level of traffic is very low - typically less than 1 kbps per system.
Multisite networking is supported between IP Office systems with differing software levels but network features will be based on the lowest level of software within the network. This option is intended to allow the phased upgrading of sites within a multisite network and it is still recommended that all systems within a network are upgraded to the same level where possible.
If larger networks are required Q.SIG can be used to link multiple SCNs together. Functionality between the communities is governed by the Q.SIG feature set.
