Session management

Supported commands, bind flow, keep-alive behavior, and session closing.

Supported commands

Command	Description
bind_receiver	Open a session to receive messages from eCall
bind_transmitter	Open a session to send messages to eCall
bind_transceiver	Open a combined send and receive session
submit_sm	Submit an SMS message
unbind	Close the session
enquire_link	Keep the session alive
deliver_sm	Receive delivery receipts or inbound SMS

Unsupported commands

These commands are not supported:

Command
replace_sm
cancel_sm
submit_multi
data_sm
query_sm

If you send one of them, eCall returns ESME_RINVCMDID (0x00000003).

Open a session

Open a session before you send or receive SMS data.

Use one of these bind commands:

Command	Description
bind_transmitter	Send messages only. You only receive command responses.
bind_receiver	Receive messages only. eCall currently sends delivery receipts on this session.
bind_transceiver	Send and receive on one session. This is the recommended mode for most clients.

Bind parameters

Parameter	Value
system_id	Your eCall username
password	Your eCall password
system_type	NULL
interface_version	0x34 (decimal 52)
addr_ton	NULL
addr_npi	NULL
address_range	NULL

eCall responds to each bind request with eCallSmpp in the system_id field.

Keep the session alive

Use enquire_link when the session is idle.

The server closes the connection after 60 seconds without traffic.

Close the session

Use unbind to close the session explicitly.

This step is optional. eCall also closes the session when the TCP connection drops.