I need the Asterisk Client and server

I need the Asterisk client and server I can’t find it on the website

http://www.asterisk.org/downloads

There is no separate client and server and, in the case of SIP, the same machine can act as both client and server in relation to a peer, even within one call.

What, therefore, do you mean by client and server.

Thanks for the help.

Can someone help me how to send sms with Asterisk

Assuming you have the infrastructure and hardware required you can use the SMS application.

https://wiki.asterisk.org/wiki/display/AST/SMS