A network technician has recently installed new VoIP phones at all employee's desks to support a new SIP cloud VoIP solution.
However, the technician is unable to make a call from the device after testing.
Which of the following should the technician verify? (Choose two.)
A.
TCP 443 is allowed. B.
UDP 1720 is allowed. C.
UDP 5060 is allowed. D.
UDP 5061 is allowed. E.
TCP 8080 is allowed. F.
TCP 8181 is allowed.
CD.
A network technician has recently installed new VoIP phones at all employee's desks to support a new SIP cloud VoIP solution.
However, the technician is unable to make a call from the device after testing.
Which of the following should the technician verify? (Choose two.)
A.
TCP 443 is allowed.
B.
UDP 1720 is allowed.
C.
UDP 5060 is allowed.
D.
UDP 5061 is allowed.
E.
TCP 8080 is allowed.
F.
TCP 8181 is allowed.
CD.
To troubleshoot the inability to make calls from VoIP phones, the technician should verify the following:
C. UDP 5060 is allowed: This port is commonly used for SIP signaling, which is the protocol used to set up and manage VoIP calls. If this port is blocked, the phone will not be able to communicate with the SIP server.
D. UDP 5061 is allowed: This port is used for secure SIP signaling (SIPS), which encrypts the signaling traffic between the phone and server. If the SIP server requires secure signaling, then this port needs to be open.
The other port numbers listed (TCP 443, UDP 1720, TCP 8080, and TCP 8181) are not commonly used for VoIP traffic, so they do not need to be open for the phones to function properly.
Therefore, the correct answers are C. UDP 5060 is allowed, and D. UDP 5061 is allowed.