|
|
|
|
FocusMTELQueue uses TCP sockets to connect to MTELPage and MTELServe applications. This page describes the operation of the sockets. TCP Packet ProtocolMTELPage drives the bulk of the operation of the protocol as it generates the messages. In the idle state the MTELQue sends watchdog packets to the MTELServe to check the connection. If the WDOG packet fails to get a response MTELQue restarts the socket. In the idle state MTELPage does not send WDOG packets to MTELQue however it relays on the MTELQue watchdog generation to MTELServe. MTELServe replies to MTELQue which in turn relays the WDOG to MTELPage. MTELPage monitors this to maintain connection to MTELQue. If the WDOG packet fails to arrive at MTELPage the familiar Failed Servers frame will appear in MTELPage. On start up of a MTELServe socket MTELQue sends a STATUS to the MTELServe. MTELServe responds with the type of server it is. It will either be a PSTN or ISDN server. MTELPage sends a RQST packet to MTELQue which is simply relayed to the appropriate MTELServe. Reponses from MTELServe back to the MTELQue are relayed back through to MTELPage. In terms of sending a message packet the MTELQue performs both a relay function and a queuing function. The queuing function depends on how many MTELServe are connected and if they are busy sending messages to other networks. The diagram below shows the packets flowing between all three applications. If there are no MTELServe available or the connection to MTELQue has failed MTELPage will fail the message immediately. If the MTELServe are busy the message is queued in MTELQue until a MTELServe can deliver the message. There is an over riding time on message delivery which is the Expirer Timer. If this time expires MTELPage will fail the message immediately and send Delete packets to MTELQue and the MTELServe to delete messages from the local queues.
MTELPage Socket ControlMTELQueue is a listener port for MTELPage clients. If the socket fails the MTELQue port will fall back to listener status immediately. MTELPage however will detect the break and then after a fallback time of 15 seconds begins reconnection. MTELServer Socket ControlMTELQueue is a client port for MTELServer listeners. The link is tested every 30 seconds and can be monitored in the Status tab of MTELQue. The response of the WDOG can also be viewed in MTELPage in the Queue entry of the menu. If the socket fails the MTELServe port will fall back to listener status immediately. MTELQue however will detect the break and then after a fallback time of 5 seconds begins reconnection. MTELPage to MDS OperationMTELPage communicates to the MDS via the MTELRelay. The MTELRelay concentrates all the MTELPgae requests into a single connection to PagerDEC. PagerDEC is the single entry point for all MTELRelays to enter messages into the MDS. Like MTELQue there is a protocol set of commands to assist in the transfer of messages. Unlike the MTELQue the MTELRelay also returns to MTELPage OAD messages for a particular region.
MTELPage /MDS/MTELServe redundancy via MTELQue and MTELRelayMTELPage communicates to the MDS via the MTELRelay. The MTELRelay concentrates all the MTELPgae requests into a single connection to PagerDEC. PagerDEC is the single entry point for all MTELRelays to enter messages into the MDS.
|
|
|
