location, and ensures support for details of the nature of the call. Feature negotiation: Not all communicating parties (which may be more than two) have the necessary features. For example, not everyone may have video support. SIP allows the group the negotiate for the features. Call participant management: SIP allows a participant to make or cancel connections to other users during a call. Users can also be transferred or placed on hold. Call feature changes: SIP allows a user to change a call’s characteristics during the call. For example, as a user, you may want to enable of disable video, especially while a new user joins a session. Media negotiation: This mechanism enables negotiation of the media used in a call, like selecting the appropriate codec for call establishment between various devices. The structure of a SIP message SIP works by having the communicating devices sending and receiving messages. A SIP message carries a lot of information which help identify the session, control timing, and describe the media. Below is a list of what a message briefly contains: •Protocol information (e.g. version) •Session information (creator, name etc.)
Running Head: IS-3120_UNIT-7_ASSIGMENT-7 •Participant information (email, phone etc.) •Bandwidth information •Encryption information •Time description (active time and repeat time) •Media description (media name, title, address etc.) •Media bandwidth information •Media encryption key What kind of security issues will the bank need to address? The security threats cause even more concern when we think that VoIP is in fact replacing the oldest and most secure communication system the world ever known – POTS (Plain Old Telephone System). Let us have a look at the threats VoIP users face.
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- Fall '13
- VoIP service provider, SIP