DTMF failure

[keithl]

This is a copy of a post on the bug reports section. Heard no answer so I've reposted here.

RFC2833 (out of band DTMF) was created because with narrowband codecs DTMF won't work in band. Even with wideband codecs (G.711), it is not 100%.

FPL handles outgoing calls perfectly, allowing G.729 and 101 (RFC2833 audio/telephone-event) to be negotiated. As of spring of this year (it worked before that), on incoming calls, FPL only proposes G.711 and not 101, forcing only inband DTMF which I have found completely unreliable. This fact I, and many others, have reported in the "General VOIP Discussions" forum.

BUT! New news! I think I have narrowed it down for FPL. I tried call forwarding to another number and found out of band DTMF is lost at FPL at the PSTN (SS7?) level, not at the SIP level. It seems FPL does not forward any incoming (PSTN) out of band DTMF. FPL seems to use it internally (voicemail) and forward it only as in band.

With this new news, can you (FPL), please look at what was changed in spring of this year that causes incoming calls to have out of band DTMF dropped (or converted to inband) at the PSTN (SS7?) level?

keithl

[FONGO_kris]

keithl,

We realize this is a bug of sorts, and it is on the list of improvements we're making over the next year. However for regular residential SIP users inbound DTMF isn't an issue because they're using an ATA or IP Phone. Yes, asterisk is a wonderful tool especially when setting up your home network around it, however that was not the way our system was built (to be used with asterisk, or similar).

Unfortunately inbound DTMF is just not a high priority for us right now, but I can assure you it _is_ in our radar as an issue.

[keithl]

Very honest answer (as always).

I'll keep checking but stop bugging you...

[ma678]

Hi there,

My outbound DTMF doesn't work most of times. For example, when I dial a calling card number, I cannot dial account number and password at all.

Any resolution?

Thanks.

[laurent]

Hi there,

My outbound DTMF doesn't work most of times. For example, when I dial a calling card number, I cannot dial account number and password at all.

Any resolution?

Thanks.

Could you please tell us what is your current Linksys ATA configuration for DTMF options, as well as codec/vocoders?

[zombie999]

Admin really needs to make a "support template". Basically, you must provide this and this or we won't help you.

Too many people with "my phone does not work....can you help me".

[laurent]

I agree Zombie, the Q&A forum should have a template to fill in for support requests. ATA brand model firmware home setup "style" and other obviousness that can easily break the whole thing...

[ma678]

ATA: SPA3102

Under Line 1 Tab
Preferred codec: G729a
DTMF process info: yes
DTMF process AVT: yes
DTMF Tx method: Auto
DTMF Tx mode: normal
DTMF Tx Strict Hold Off Time: 40

Any advice?

Thanks.

[zombie999]

Those settings work fine on my ATA for DTMF.

You could changing codec to G711u. If it still does not work, change the DTMF mode to INBAND.

[watermark]

FPL may intend to block outside DTMF for some reasons. Inside DTMF is fine. When I call in my own phone number for voicemail (98* doesn't work) with my own sip device, keypad is responsive. My sip dtmf setting is rfc2833.