C# SMS API keepalive

To keepalive the IP SMS link between the C# SMS API and the sms gateway you need to estabilsh a permanent connection with the C# SMS API's connect method. The system will automatically send keeplive requests.

C# sms api keepalive ping
Figure 1 - C# sms api keepalive

The C#/.Net SMS api keepalive procedure

To send keepalive requests from the C#/.Net SMS api simply keep the connection open

  • Step 1: Create connection
  • Step 2: 30 seconds of inactivity
  • Step 3: Send keepalive to keep the TCP/IP link open

C# sms api keepalive example:

Client.Connect(host,port,user,pass);
...
Keepalive packets are sent automatically if there is no traffic
...
Client.Send(msg);

Keepalive packets are neccessary because firewall rules, vpn connections or dynamically allocated IP SMS routes on the Internet could be disconnected after a period of inactivity. By sending keepalive packets both the C# SMS API client and the SMS gateawy can be certain, that the connection is still open.

Keepalive packets are only sent if no other SMS traffic is moving on the link.

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