Does Android app needs to request again for registration on SERVICE_NOT_AVAILABLE message in C2DM?

I have implemented C2DM in one of the applications and its working properly. Sometimes, what happens that when registering for C2DM the error message comes as SERVICE_NOT_AVAILABLE. Now, in C2DM docs its mentioned that the application should back off an开发者_开发知识库d try later. I wanted to know that whether its mobile application that should back-off and again try to register or will the server back-off and send the registration id whenever it can.

That message means no registration id could be provided, and the solution is for your app to retry. It's recommended that when requesting a registration ID that you keep trying, because if your app doesn't have one, core features that rely on push messaging will not work.