Chapter 26: Security - Avaya 1230 Administration

Chapter 26: Security

This section specifies the behavior of the following security features:
• SIP over TLS
• Connection persistence
• SRTP
• SFTP
• SSH
SIP over TLS
To avoid security problems such as message integrity attacks, SIP over TLS uses Transport Layer
Security (TLS) to provide secure communication between the IP Deskphone and the SIP proxy.
Transport Layer Security (TLS) protects SIP signaling traffic. It sits on top of the Transmission
Control Protocol (TCP), the preferred default protocol for SIP traffic. You can use TLS with a user
name and password to provide a means of server-only authentication. IP Deskphone-specific Public
Key certificates can provide even stronger mutual authentication of both the server and the IP
Deskphone.
Using SIP over TLS protects SIP messages on a hop-by-hop basis. To achieve complete end-to-
end security through the use of TLS, each element involved in the system must also be capable of
securing SIP traffic using TLS.
Connection persistence
Connection persistence allows the IP Deskphone to establish a connection and monitor the
connection for failure by using "keep-alive requests.
The IP Deskphone establishes connection with the proxy using the commonly accepted ports.
Periodically, based on a configured timer value, the IP Deskphone issues a request to the server to
verify that the connection with the server at the TCP level is still active. When the IP Deskphone
discovers that the keep-alive packet has not been answered, it attempts to reestablish a connection
with the proxy. If this is successful, the IP Deskphone reregisters with the proxy (and sends a new
subscription requests where appropriate). If it is not possible to reestablish the connection, the IP
March 2015 SIP Software for Avaya 1200 Series IP Deskphones-Administration
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