[Asterisk-Users] Experience sharing on Planet VIP-450 + Asterisk

[Steve Totaro]

> 
> Hi all,
>    Previously I have asked about stopping iLBC in Asterisk, and I
would
> like to use G.711 u-law only. Actually I have tried entirely remove
> anything file related to "ilbc" in /usr/lib/asterisk/modules, but it
still
> didn't work. The error message about the improper RTP packet length
still
> there, and I still can't make DTMF detection work.
>    What's next? Well... thanks to the buggy firmware and imcompatable
> standard with Asterisk...
> 
>    First of all, I can't deny that Planet VIP-450 does a good job in
> packetizing voice stream, the voice quality is really good and delay
is
> really small. Also the hardware itself is quite robust, it seldom
halt..
> (the machine has been up for a few days). Also it is quite
feature-rich, I
> can say. BUT I think there is quite a number of BUGS in the firmware!
> 
>    In order to see which kind of DTMF Relay it is using, I have done a
> packet analysing. When I try to pass SIP INFO type DTMF band to
VIP-450,
> it replies "501 Unimplemented". Also when I try to pass DTMF from my
POTS
> phone via the FXO port, only RTP payload can be seen in the packet
> captures. I DID suspect that it is RFC2833, because as far as I know
> RFC2833 did have the DTMF textx inside the RTP packet somewhere (seems
> header). But asterisk just simply did not regconize them (of coz I
have
> set DTMFmode=rfc2833)! It is pretty strange that the user manual
states
> "VIP handles DTMF Relay per SIP specification". So VIP-450 actually is
> using what kind of SIP specification?
> 
>   How about using its Inband DTMF relay? This will certainly generate
> strange warning just like my case : improper ilbc frame size and tell
me
> to use u-law to do DTMF even if I AM using G.711 u-law. It is seems
that
> the DTMF tone generated by VIP-450 generate is kinda strange...
> 
>   So the final solution is, SIMPLY SWITCH OFF THE DTMF RELAY IN
VIP-450.
> Please try to type "show coding" in console mode and you will see a
lot of
> coding (codec) profiles. Most of them are with DTMF relay. Just switch
off
> them by "set coding <profile id> dtmf_relay off" (please check with
the
> manual). If you want to stop certain codec, just simply make that
coding
> profile unusable in voice. For example, "set coding <profile id> voice
> off". If you only turn on the profile with u-law, the SIP header it
issues
> will just consist of 0x4 (ulaw) codec, not 0x105.
> 
>   In my point of view, Planet is expecting this device is connected to
> another VIP-450, not really for Asterisk or anything else, even not
for a
> soft phone. Certainly this is not enough for everyone, at least I
can't do
> any IVR and something what a PBX should have (just like what I can do
in
> Asterisk). I hope my experience will help anyone who is using VIP-450
with
> Asterisk, just like me. I have done Googling for 3 days but I can
search
> for nothing related to this issue. Sorry for my poor written English.
> 
> Cheers,
> Jason Chan, Hong Kong

You should post this stuff and future findings on the wiki.

Thanks,
Steve