VoIP: Odom's & Lammle's book inconsistency

bermovick

Odom's 'CCENT/CCNA ICND1 Official Exam Certification Guide', page 145, under User Datagram Protocol, 2nd paragraph states "...VoIP uses UDP because...".

Lammle's 'CCENT Cisco Certified Entry Networking Technician Study Guide', page 81, last paragraph before it begins discussing UDP Segment Format says "So if you're using Voice over IP (VoIP), for example, you really don't want to use UDP, ..."

I suppose it really doesn't matter at this point, but that's a bit worrisome

notgoing2fail

VOIP is definitley UDP, there's no way it can carry voice streams with TCP.

I'm not sure what the entire context of what Lammle was referring to about not using UDP....so I don't want to say too much....he might be trying to make a different kind of point...???

jeanathan

RTP protocol uses UDP as a transport mechanism and is related to actual packets containing vocal samples that are later reconstructed to play back voice through a speaker.

I think as a network engineer you are going to look at RTP when talking of VoIP at the CCNA level because it is what you will have to deal with on occasion.

RTCP uses TCP and does call setup and teardown. Likewise, SIP can use TCP as its transport mechanism. As a VoIP technician you will need to know RTCP and SIP, but at the CCNA level talking about VoIP probably is contained to the RTP protocol and its transport UDP.