Destination networks, also known as Service Network Access Points (SNAPs) avoid the connectivity problems that are related to the access point being fixed for the duration of the data connection. With the availability of WLAN and other data bearers, the number of access points has grown considerably. With WLAN, the availability of an access point can change frequently. A fixed access point in selection often leads to a poor access point choice. Because the network environment is now more dynamic, you can have either a safe but slow connection, or a fast but unreliable connection. In practice this means that the application is either stuck with using GPRS or the user must continuously change the settings to point to the WLAN access point that happens to be available. A fixed access point leads to non-optimal usage of available connections, especially with applications that use long-lasting data connections.
Applications should monitor the connection state by using platform services (such as Connection Monitor Server API) and avoid polling and keep-alives. If the application protocol mandates the use of timers, they should be tuned so that the control data over the air is minimized.
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