Call-ID is generated by the combination of a random string and the softphone's host name or IP address. The combination of the To tag, From tag, and Call-ID completely defines a peer-to-peer SIP relationship between two users and is referred to as a dialog. It MUST be the same for all requests and responses sent by either User Agent in a dialog. It SHOULD be the same in each registration from a User Agent.
All SIP User Agents must have a means to guarantee that the Call-ID header fields they produce will not be inadvertently generated by any other User Agent. Note that when requests are retried after certain failure responses that solicit an amendment to a request (for example, a challenge for authentication), these retried requests are not considered new requests, and therefore do not need new Call-ID header fields.
Use of cryptographically random identifiers in the generation of Call-IDs is RECOMMENDED. Implementations MAY use the form "localid@host".
callId- the string value of the Call-Id of this CallIdHeader.
java.text.ParseExceptionwhich signals that an error has been reached unexpectedly while parsing the callId value.
objthe object to compare this CallIdHeader with.
objis an instance of this class representing the same CallIdHeader as this,