Telesis ITS821 Executive IP Telephone Set
ITS821 is the IP version of the DTS821 digital set. It is specially designed for Telesis Hybrid IP PBX Business Phone Systems and the X1. The applied VoIP protocol is Telesis xSIP (eXtended SIP) protocol, which allows value added services of the DTS set to be functional over IP.

ITS821 in white color
Beyond the comfort and availability of value-added services, xSIP also allows secure communication with utilizing AES-256 media encryption. Telesis Business Phone Systems, TDM-IP Telephony Switches, as well as ITS821 Executive IP Telephone Sets support AES-256 over xSIP protocol.

Telesis ITS821 IP telephones connected to a Telesis system. AES 256 media encryption over xSIP
Security of VoIP communication between an ITS821 IP Telephone Set and a Telesis IP Telephony System is ensured with:
- Telesis developed protocol: xSIP
- proprietary VoIP codes
- intelligent algorithms for authentication
- exchange of Diffie-Hellman half keys
- cipher AES-256
Furthermore, the media encryption solution with ITS821 Telephones:
- is easy-to-install
- usually does not need to tackle Firewall and NAT issues
- is easy-to-manage and -operate
- may operate anywhere with the internet connection
- is cost-effective
- needs a small bandwidth
- is protected against Man-in-the-Middle Attacks