Recently I had the opportunity to try a SIP videophone unique: it is produced by SVP SBNTech 5000.
The key features of this product are:
- Videophone Calls over the Internet
- Touch Screen LCD (10.2 × pollici/800 480)
- Compliant with IETF standards, ITU-T
- User-friendly interface
- Video calls @ 30 FPS
- Digital Photo Frame as a Screen Saver
- Integrated Web Browser
- SD Card Slot & USB 2.0
- WiFi (802.11b/g/n)
- Bluetooth (option)
- An FXS port
- Integration HSDPA
- Video / Audio Input / Output
- Camera / LCD Power Save Mode
- Support for audio codecs g711/g729a
- Support for H.264 video codecs and h263 (QCIF / CIF / QVGA / VGA)
Tests were conducted using both Asterisk 1.4.x on CentOS that Asterisk 1.6.x on Ubuntu Server in both cases installed from source. The configuration used for the tests was as follows:
[general]
videosupport=yes; abilita il supporto video in asterisk
maxcallbitrate=384
[300]
secret=passwordchevuoitu
type=friend
host=dynamic
qualify=yes
context=from-internal
disallow=all
allow=h264
allow=h263
allow=g729
allow=alaw
canreinvite=yes
maxcallbitrate=384
[301]
secret=passwordchevuoitu
type=friend
host=dynamic
qualify=yes
context=from-internal
disallow=all
allow=h264
allow=h263
allow=g729
allow=alaw
canreinvite=yes
maxcallbitrate=384
In principle, I suggest you avoid, as far as possible a configuration where you have to worry about Asterisk to retransmit the audio / video streams to the two end points. This is why, in the suggested configuration, the parameter "canreinvite" is set to "yes."
The parameter "canreinvite = yes" Asterisk allows it, once the call has been accepted, to send a new INVITE message to the two endpoints with the information necessary for the establishment of an audio / video communication directly between them.
Please note that this "Resubmit" will not happen, despite "canreinvite = yes", if:
1) one of the two clients is configured with "canreinvite = no";
2) if the clients are using different codecs.
3) If the command dial () contains the parameters for recording (W w) / call transfer (to T) / forced hangup (I H).
In all cases, the required bandwidth for a video call is still at least 200kbps, provided that the canreinvite is enabled. In other cases need more bandwidth. Note that, as soon as an active video call, mobile value using bandwidth as low as possible. To get better video quality must increase bandwidth parameter dall'apposito hand panel configuration call.
In my testing I used: H264 / G729 / VGA. It 's always possible to scale the parameter QVGA or QCIF to VGA if you want to further decrease (although not by much) the required bandwidth.
The tests carried out also seems that only when canreinvite operates a call between a mobile phone and the video board is not active in the first video. In other cases, goes hand-selected to not activate the video when you make or accept the call from the video phone.
Very intuitive and simple user interface: all functions are easily accessible thanks to a convenient touch.
The product was kindly made available by www.4geek.it
The manufacturer's page: SBNTech
Tags: Call Center Systems | VoIP PBX | Asterisk Consultant Naples | PBX Phone | VoIP | Asterisk CTI | PBX | IP Phones | Networking | Linux
Development of IVR systems, call center, VoIP PBX.