Ensure that the 1100 and 1200 series phones within a branch are all Centralized or all IP Office users, otherwise you must configure each phone manually.

In the Rainy day mode, direct media with SRTP is not supported. In this scenario, media is anchored on IP Office.

The address book feature of the phone varies for different servers. Hence, the contacts added to the phones while the phones are connected to Session Manager are unavailable when the phones are connected to IP Office, and vice versa.

Install the security certificate manually. You must accept the authorization prompts from the phones to go ahead and install the certificate. If you do not provide any input, then the certificate does not get installed.

1100 and 1200 series phones support only two servers. You can deploy this phone as Centralized users in branches that connect to a single Session Manager and configure it with the local branch IP Office as the secondary server. However, you cannot deploy this phone as Centralized users in a branch that is configured to two Session Manager. If there are Centralized 1100 series or 1200 series phones in the branch, then you must not configure the IP Office and other Centralized phones in that branch to two Session Manager. If you configure the IP Office with two Session Manager, then the Centralized 1100 series and 1200 series phones will receive no service. This occurs if the primary Session Manager is down and the secondary Session Manager is still reachable from the IP Office. The Centralized 1100 series and 1200 series phones will not be able to register to the IP Office that will still be in Sunny day mode.