What is RTP and What Do I Need to Know About It?

[Phillip]

Hi All,

In my case, newbie is appropriate. I have been involved in the development of digital voice encoding technology, but my work was far removed from applied telephony, network protocols or VoiP technology. What I know about networks you could fit on a tic-tac-toe board.

I have been reading a lot of threads and topics where RTP is mentioned. I understand that this has something to do with network packets but I am otherwise ignorant. Perhaps there is a related term I might recognize? But in terms of how various configuration parameters are set, what do I need to know about RTP?

[QBZappy]

More than you ever need to know can be found here:
   
3-part on SIP protocol
http://www.obitalk.com/forum/index.php?topic=4551.0

[Phillip]

Hi QBZappy,

Thanks for the links. But its really kind of overwhelming.  I am currently wading through the technical explanation of SIP you linked, however I was still wondering; at this time and at my level of my expertise, is all of this really necessary? Don't get me wrong. I will over time begin to internalize this information. But could you give me the short version? Pleeease? I'm memorizing as fast as I can! Technical articles aren't something I usually speed read.

What does RTP stand for? I haven't run across it as such and I'm about halfway through the articles. So in layman's terms, what is it? And finally, how much do I really need to know about it to apply the configuration advice I am reading on this site?

[jwcmb]

I thought the Wikipedia article was a nice summary of the Real-time Transport Protocol and its role in IP telephony: http://en.wikipedia.org/wiki/Real-time_Transport_Protocol

As far as what you need to know to configure and use your Obi device, my own personal opinion is that the following are initially a much better use of your time than poring over technical articles:  (1) carefully reading and searching the forum posts here and the Obi Device Admin Guide (which I believe are both excellent resources), and (2) digging right in and gaining experience making some configuration changes and seeing the results.

[QBZappy]

I have been reading a lot of threads and topics where RTP is mentioned. I understand that this has something to do with network packets but I am otherwise ignorant. Perhaps there is a related term I might recognize? But in terms of how various configuration parameters are set, what do I need to know about RTP?

In a nutshell this should suffice as an explanation to get you started.

A sip call has a signaling part (rings the phone) and another part which passes the voice conversation part (media). The RTP settings in the OBi control which ports to use for the voice conversation part. There is usually no need to change these values (port numbers) unless it conflicts with another app or another voip setup, which may be using the same port numbers.

You are expected to take an exam based on those articles you are reading. Note that a passing mark is 75%. 

[Phillip]

Thanks my friend. That helps a lot.

I am going to start a new thread and post the list of hardware I am using (only 1 OBi100 involved) and what my goals are (probably too lofty).  You seem to have an encyclopedic knowledge of what is on this forum and what can be done with an OBi. When I do, your input would be great! I have already followed a bunch of your links. They have helped me a lot.

PS. As soon as I get another commission check, I'll spring for the pizza!  Btw, who generally gets the beer?

[Phillip]

So THAT'S what it means! Thanks.

Great advice, gwcmb. But when everyone speaks in acromyms, its sometimes necessary to ask, 'Huh?' 

I thought the Wikipedia article was a nice summary of the Real-time Transport Protocol and its role in IP telephony: http://en.wikipedia.org/wiki/Real-time_Transport_Protocol

As far as what you need to know to configure and use your Obi device, my own personal opinion is that the following are initially a much better use of your time than poring over technical articles:  (1) carefully reading and searching the forum posts here and the Obi Device Admin Guide (which I believe are both excellent resources), and (2) digging right in and gaining experience making some configuration changes and seeing the results.

[Ostracus]

VoIP relatively speaking is still in it's infancy, and a lot of inner workings are flying free for all to see. Just imagine all the techno-jargon that's behind the scenes of a Pots call, as simple as it first appears.

[Phillip]

I know Ostracus. I know...

Someone gave me a SPA3102 a while back. I tried searching the web to gather configuration examples and technical articles. I felt like I stepped through a wormhole. That's what convinced me to get an OBi. Slap me please, I thought it would be easy.  I am waaaay outside of my comfort zone and everyone talks to me like I should know this stuff.

I had a close friend that was well versed in communication systems, from Ma Bell to Langley to Jackass Flats. He passed away a couple of years back. I really miss him.

I was pretty well versed in dedicated microprocessor systems and certain aspects of design and programming. We collaborated on a patent for a cell phone vocoder. But I would end up in a conversation with him about phone systems and we were suddenly speaking Ugaritic for all I knew.

I started another thread about configuring voice gateways and Toll Free Terminal providers. Same story. There are plenty of answers couched in acronyms, jargon and poorly explained syntax, but very little real guidance. I guess people get tired of explaining what they posted elsewhere. But I have read their posts and it might be the same topic but written for a different application on a different device with different features. Or it may have been written a half-dozen firmware versions ago. Or it might just be hard to understand for a newbie.

A few have been very helpful. QBZappy stands out. But mostly I get cryptic responses if at all.

My wife is starting to threaten me because of all the time I'm spending. There's reading technical material, trying to get up to speed here while trying to keep my little home business afloat. Oh! And trying to get someone to speak to me in layman's terms. Honestly, I feel like I just stepped into a sinkhole.

This is getting depressing. It's more like a 'through the looking glass' version of OBi WAN conundrum. If this is the learning curve on an OBi100, AT&T (whom I despise) is starting to look better all the time.

Crap. I'm going to bed. Maybe I'll dream that I'm Captain Jean-Luc Picard and that Q just popped into 10 Forward, laughing at me, only to explain why this or that digitmap or callroute isn't possible in this universe, but if I want to follow him to the next...