Some general questions about H.323 and SIP
Posted: Thu May 27, 2010 1:52 pm
Hi erverybody!
My name is Stefan, I'm from Germany and at the moment I'm writing my diploma thesis about VoIP over WLAN / WiFi. While studying some Websites and Books I found out that most people think SIP is best fitting for VoIP. Finally I found this Website and it made me happy to see some arguments form an other point of view because most of these websites don't explain why SIP is much more better than H.323. I jut wanted to ask some questions and tell you my point of view. Feel free to comment, critcise or correct my theories, questions and statements.
1. Nowadays most users (at home or with mobile phones) are using SIP for Voice. H.323 is mostly used in corporative networks and for video conferencing. I've read that SIP is growing in these areas too. But in the HD-video area vendors like Cisco only using H.323. Is this all true or are there any differences what you believe or know?
2. SIP nowadays is the most used VoIP protocol because it has the ability to add services and extensions easily . It's easier for programmers to learn it and create new applications. If you just need a voice capable ip-phone a vendor has less programming efford because they only need to add the voice extensions. H.323 has to be compatible to every other H.323 application. I read this somewhere in the internet and there were no references so I'm not sure if this really is true.
3. Nowadays SIP and H.323 have a lot of things in common and most SIP/H.323 can do H.323/SIP can do also. So what are the features of SIP and H.323 that stand out the most ? Which advantages and disadvantages are relevant regarding todays usage?
4. The future is NGN but SIP and H.323 are not fitting perfect into this. So H.325 or an alternative protocol is going to take over the market some day. How long will this take? Maybe 10 15 years or will there a hype about this? What do you think?
5.If I want to implement a VoIP structure for a company with 100 VoIP users. The users will have IP-Phones and WiFi-IP-Phones and maybe some will also have Softphones. The users will call each other in that company and also people located anywhere in the world (whatever they are using VoIP or ISDN or something else). What benefits would H.323 deliver which SIP can't. I think maybe the interoperability with the PSTN would be better with H.323. If the Users want to do video calls this would also be an advantage of H.323. What else could turn the balance to H.323? Maybe there would be more different Vendors/Products for SIP, so maybe the devices would be cheaper (because they haven't got the features of H.323 devices)?
Thank you for any response. Even it's only for one Question/Statement. I'm new at this topic so I just want to get in contact with developers and users who have several years of knowledge and practise in VoIP/SIP/H.323 and want to share their experience.
Thanks a lot!
Stefan
My name is Stefan, I'm from Germany and at the moment I'm writing my diploma thesis about VoIP over WLAN / WiFi. While studying some Websites and Books I found out that most people think SIP is best fitting for VoIP. Finally I found this Website and it made me happy to see some arguments form an other point of view because most of these websites don't explain why SIP is much more better than H.323. I jut wanted to ask some questions and tell you my point of view. Feel free to comment, critcise or correct my theories, questions and statements.
1. Nowadays most users (at home or with mobile phones) are using SIP for Voice. H.323 is mostly used in corporative networks and for video conferencing. I've read that SIP is growing in these areas too. But in the HD-video area vendors like Cisco only using H.323. Is this all true or are there any differences what you believe or know?
2. SIP nowadays is the most used VoIP protocol because it has the ability to add services and extensions easily . It's easier for programmers to learn it and create new applications. If you just need a voice capable ip-phone a vendor has less programming efford because they only need to add the voice extensions. H.323 has to be compatible to every other H.323 application. I read this somewhere in the internet and there were no references so I'm not sure if this really is true.
3. Nowadays SIP and H.323 have a lot of things in common and most SIP/H.323 can do H.323/SIP can do also. So what are the features of SIP and H.323 that stand out the most ? Which advantages and disadvantages are relevant regarding todays usage?
4. The future is NGN but SIP and H.323 are not fitting perfect into this. So H.325 or an alternative protocol is going to take over the market some day. How long will this take? Maybe 10 15 years or will there a hype about this? What do you think?
5.If I want to implement a VoIP structure for a company with 100 VoIP users. The users will have IP-Phones and WiFi-IP-Phones and maybe some will also have Softphones. The users will call each other in that company and also people located anywhere in the world (whatever they are using VoIP or ISDN or something else). What benefits would H.323 deliver which SIP can't. I think maybe the interoperability with the PSTN would be better with H.323. If the Users want to do video calls this would also be an advantage of H.323. What else could turn the balance to H.323? Maybe there would be more different Vendors/Products for SIP, so maybe the devices would be cheaper (because they haven't got the features of H.323 devices)?
Thank you for any response. Even it's only for one Question/Statement. I'm new at this topic so I just want to get in contact with developers and users who have several years of knowledge and practise in VoIP/SIP/H.323 and want to share their experience.
Thanks a lot!
Stefan