BlackBerry Spark Communications Services Guide

Multiple Points of Presence (MPoP)

Spark Communications Services allows your application to have multiple instances running and connected at the same time for the same user. This ability is referred to as having Multiple Points of Presence, or MPoP.

The MPoP feature works by managing two distinct aspects of a user's representation within the system.

In MPoP, each identity can run multiple endpoints simultaneously. Each endpoint can send and receive messages, start and leave chats, mark messages as read, etc.

Endpoint Types

Spark Communications Services supports two kinds of endpoints.

Persistent endpoints can be used offline even when they aren't connected to the BlackBerry Infrastructure. Ephemeral endpoints do not have persistent data so there is only limited functionality when no connection to the BlackBerry Infrastructure is available.

Endpoint Management

Spark Communications Services limits the number of endpoints of each type that an identity can have connected to the BlackBerry Infrastructure at the same time. The way that these limits are enforced reflects the differences between the two types of endpoints.

The BlackBerry Infrastructure limits each identity to a maximum of three concurrently registered persistent endpoints and seven concurrently registered ephemeral endpoints. Your application must expect these limits to change at any time for new and existing identities. The SDK does provide information about the current limits when performing Endpoint Management.

Persistent Endpoint Management

Persistent endpoints are expected to be entities that the end user is aware of. For example, a user knows that they have a copy of your application running on their Android phone and another copy on their iOS tablet. Your application can use the Endpoint Management features of the SDK to list what endpoints are registered, give each endpoint a name and description, or deregister an endpoint from their identity.

When a persistent endpoint is created, it first registers with the BlackBerry Infrastructure. If it passes various security checks, it is allowed to connect. When the BlackBerry Infrastructure detects that the maximum number of persistent endpoints has already been reached, your application must deregister one or more of the existing persistent endpoints to make room for the new one. Alternatively, your application can decide to deny the registration of the new endpoint.

Persistent endpoints have the ability to list and manage ephemeral endpoints.

Ephemeral Endpoint Management

The management of ephemeral endpoints is more automatic. These endpoints are created for brief use, so it is important that they are cheap and easy to make. When an ephemeral endpoint registers with the BlackBerry Infrastructure and the maximum number of ephemeral endpoints has already been reached, the BlackBerry Infrastructure selects a less-active, older ephemeral endpoint and automatically deregisters it. Ephemeral endpoints that are deregistered do not automatically try to reregister, but they do allow your application to reregister them (which might deregister another ephemeral endpoint).

Ephemeral endpoints do not have the ability to list or manage any types of endpoints.

Synchronization

All endpoints of the same identity see the same data at the same time if they are all connected to the BlackBerry Infrastructure. When endpoints are offline for a short time and then come back online, they synchronize by receiving messages and other information from the BlackBerry Infrastructure, like a single endpoint does when it disconnects and then reconnects.

Examples of information that is synchronized across an identity's endpoints include:

Some state information and data is local to an endpoint and is not synchronized with other endpoints of the same identity. Sometimes this is because the data only pertains to the endpoint, and sometimes this is because the state hasn't propagated to other endpoints yet.

Examples of information that is not synchronized across an identity's endpoints include:

Key Synchronization

All endpoints in an identity use the same identity keys and chat keys, and all endpoints have access to the same user keys.

If your application uses the BlackBerry Key Management Service, the SDK synchronizes all of these keys across all endpoints automatically.

If your application uses Cloud Key Storage, then when it fetches and stores keys as directed by the SDK, all of these keys are kept synchronized across all endpoints.