Because of its extensible and open nature, Session Initiation protocol has been the preferred call control protocol for VoIP networks. SIP, which is open and extensible, is critical to the integrity of call signaling among sites. If left unprotected, SIP can be exploited by attackers. Secure SIP refers to a security protocol that allows SIP messages to be sent over a Transport Layer Security encrypted channel. TLS was originally used to secure HTTP sessions. However, it can now be used to protect SIP session communication from eavesdropping and tampering. Network administrators can enjoy increased security by deploying SIP-based devices with Secure SIP.
All SIP proxy servers and user agents must implement Message Digest 5 authentication as the minimum level of security. This is a simple authentication challenge that can be used by both a SIP proxy server and a SIP user agent. Secure Multipurpose Internet Mail Extensions (S/MIME), can be used to encrypt data within SIP messages. SIP support for S/MIME is not as widespread as HTTP due to the need for public-key infrastructure support as well as the additional complexity of managing security certificates. Secure SIP is a way to run SIP over TLS hop-by-hop. This provides greater security than basic MD5 authentication without the extra overhead that comes with S/MIME.
SIP protocol and HTTP protocols have a key differences. A SIP request can travel through multiple hops before it reaches its destination. SIP over TLS is a way to provide secure connections hop-by-hop. We are offering the USA Virtual Phone Number service in the US(937 area code,938 area code)and many other services. We are also specialized in different products, Call Nation and Prepaid Mall. If you want to know about sip call forwarding, visit the sip call forwarding.