SIP Request Methods for Migration from PRI to SIP:

SIP Request Methods for Migration from PRI to SIP

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A voice engineer is preparing to migrate from PRI to SIP.

Which three SIP request methods are available? (Choose three.)



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A. B. C. D. E. F.


The correct answers to the question are B. PRACK, E. OPTIONS, and F. TRYING.

Here's a brief explanation of each SIP request method:

  1. PRACK (Provisional Acknowledgement): This request method is used to acknowledge the receipt of a provisional response (1xx) to an INVITE request. PRACK is used to confirm that a provisional response was received, even though the final response has not yet been received.

  2. OPTIONS: This request method is used to query a server about its capabilities. The server responds with information about the methods it supports, the codecs it can handle, and other relevant information.

  3. TRYING: This response code is sent by a SIP server to indicate that it has received a request and is processing it. The TRYING response is used to acknowledge receipt of a request and to prevent retransmission of the request.

UNAUTHORIZED, USE PROXY, and NOTIFY are not request methods in SIP. UNAUTHORIZED is a response code used by SIP servers to indicate that authentication is required, USE PROXY is a header field used in SIP messages to indicate that the request should be forwarded to a proxy server, and NOTIFY is a request method used to send asynchronous notifications about the status of a subscription.

In summary, PRACK, OPTIONS, and TRYING are the correct SIP request methods available.