Specifications

Chapter 10 – Internet Service Commands
Multi-Tech Systems, Inc. AT Commands for EDGE (E1) Modems (S000474A) 163
6, with an error being returned no earlier than after sending the first AT^SISR or AT^SISW command. In URC
mode, an error URC, such as "Host not found" would be received in this situation, but in polling mode the only
way to detect the state is using AT^SISI or, alternatively, AT^SISO.
• If the user rapidly closes and opens TCP/IP connections based on the embedded TCP/IP stack the service
may display the error "No buffer space available", meaning that all TCP/IP socket resources are exhausted. In
the worst case, opening further TCP/IP connections is locked for up to 60 seconds.
• The Socket Listener may not work properly if the service is re-opened shortly after having closed the Socket
Listener. To ensure that the service works correctly the host is required to wait at least two minutes before
reopening a Listener.
• Usage of the PIN is dependent on conditions specified for the command. Not all command types are PIN
protected (for example a write command can be PIN protected while the read command is not). Note: The
table provided in Section 19.3, Available AT Commands and Dependency on SIM PIN uses the same symbols.
• This command is not supported in airplane mode.
10.5.1 Example: Accepting/Rejecting Socket Connection Request from Remote Client
Host 1 configured as Socket listener with IP address 10.10.0.187 at port 65534 is receiving a connection request from
the remote client 10.10.0.185 (at port 1024). The example assumes that connection and service profiles have been
created as stated earlier.
Start the Socket service in listener mode, then query the IP address dynamically assigned to the Socket
listener:
at^siso=4 Host 1 opens the Socket service.
at^siso? Query the current status of all services. All service profiles are
unused, except for service profile 4 which is running in listener
mode, where <srvState>=3 (listening) and <socketState>=3
(LISTENER). The response also indicates the IP address
dynamically assigned to the listener. The listener’s access data
(IP address and TCP port number) shall be passed on to the
client.
^SISO: 0, “”
^SISO: 1, “”
^SISO: 2, “”
^SISO: 3, “”
^SISO: 4, “Socket”,”3”,”3”,”0”,”0”,”10.10.0.187:65534”,”0.0.0.0:0”
^SISO: 6, “”
^SISO: 7, “”
^SISO: 8, “”
^SISO: 9, “”
OK
Indication of incoming Socket connection request:
^SIS: 4, 1, 0 The URC indicates that the listener configured on service
profile 4 is receiving a Socket connection request
(<urcCause>=1) from the remote client. The last URC
parameter <urcInfoId> represents the ID of the dynamically
assigned service profile, here 0.
at^siso? Query the current status of services.
^SISO: 0, “Socket”,”2”,”4”,”0”,”0”,”10.10.0.187:0”,”10.10.0.185:1024” Indication on host 1 that the
connection request from the
remote client has been
dynamically assigned to service
profile 0 which is set to Server
mode (<socketState>=4).
^SISO: 1, “”
^SISO: 2, “”
^SISO: 3, “”
^SISO: 4, “Socket”,”3”,”3”,”0”,”0”, “10.10.0.187:65534”,”0.0.0.0:0”
^SISO: 6, “”
^SISO: 7, “”
^SISO: 8, “”
^SISO: 9, “”
OK