Troubleshooting
Outbound calls refused
When we refuse an outbound call, your PBX receives one of these SIP responses. Some responses have more than one cause, so check each one listed.
Organisation call limits ship with the org-limits release.
| Response | Cause | What to do |
|---|---|---|
400 Bad Request | The called number in the Request-URI is not in E.164 format with + | Send + and the country code, for example +91XXXXXXXXXX. We do not rewrite 0-prefixed, 91-prefixed or 10-digit numbers |
403 Forbidden | The caller (From user) is not a phone number | Set the From user to one of your attached numbers in E.164 format |
403 Forbidden | The caller is not one of the numbers attached to your trunk, or it is attached to a different trunk from the one in the Request-URI | Use a number attached to this trunk. Check the attached numbers on your trunk |
403 Forbidden | Your trunk is suspended | Email hello@superfone.in |
403 Forbidden | Your wallet balance is Rs. 200 or below | Top up your wallet |
404 Not Found | The Request-URI host is not a valid trunk FQDN | Use your FQDN exactly as issued, in lowercase: <label>.sft.superfone.co.in |
405 Method Not Allowed | Your PBX sent REGISTER or another unsupported request | Turn off registration. See Supported SIP methods |
480 Temporarily Unavailable | The caller is not a Superfone number | Use one of your attached Superfone numbers as the caller |
503 Service Unavailable | The trunk, or your organisation, is at its CPS or concurrent-call limit | Pace new calls and retry after a short delay. To raise your organisation's limit, email us. See Capacity limits |
503 Service Unavailable | We could not confirm your wallet balance, or the call could not be placed on the phone network right now | Retry after a short delay. If it continues, email us |
No response at all
If your PBX gets no response, check that it sends to port 5060 over UDP or TCP and that your firewall allows the replies. We may also drop SIP traffic without replying when one address sends an unusually high number of requests in a short time.
Inbound calls not reaching your server
Check these in order:
- The number is attached to your trunk. A number that is not attached is handled like any other Superfone number and never reaches your server.
- The trunk is active. While a trunk is suspended, calls are not delivered to your server.
- Your wallet balance is Rs 200 or lower. You must maintain more than Rs. 200 to make or receive calls.
- The trunk and your organisation are under their limits. Calls over a CPS or concurrent-call limit are not delivered. Your organisation's limits are shared by all your trunks and SFVoPI apps.
- Your server can be reached on your trunk's transport. The host is public, the port is right, and your firewall accepts SIP over that transport, and RTP, from our network addresses. See Inbound calls fail on the transport you chose.
- Your server answers within 60 seconds. After 60 seconds without an answer, the call ends.
- Your server accepts G.711 A-law (
PCMA).
Inbound calls fail on the transport you chose
Inbound calls do not reach your server, or the caller hears no audio. When the trunk is set to tcp and your firewall blocks TCP from us, the call fails after about ten seconds, not straight away.
The usual cause is that your server cannot be reached on the transport set on your trunk. Either your firewall does not accept SIP from our signalling addresses over that transport, or nothing on your server is listening on it.
Check these:
- The transport on your trunk. Get your trunk and read
customer_sip_transport. - Your server listens on that transport. It must accept SIP over that transport on the host and port set on your trunk. A server that listens only on UDP does not receive calls when the trunk is set to
tcp. - Your firewall accepts it. Allow SIP from our signalling addresses over that transport. Keep accepting RTP from our media addresses as well. Media is RTP whichever transport you set.
- Switch back if you cannot open TCP. Update your trunk and set
customer_sip_transporttoudp.
No audio or one-way audio
- If inbound calls have no audio and never reach your server, see Inbound calls fail on the transport you chose.
- Make sure your firewall accepts RTP from our media addresses, and that your server sends RTP back to the address and port in our SDP.
- If your server is behind NAT, make sure it puts its public address in its SDP.
- Make sure your server offers or accepts
PCMA. We do not transcode.
Errors when attaching a number
| Status | Message | What to do |
|---|---|---|
400 | Invalid voip_number: <number> | Write the number in E.164 format, for example +91XXXXXXXXXX |
400 | Number(s) not allocated to this org: <numbers> | Only Superfone numbers on your own account can be attached |
409 | Number(s) already linked to a VoPI app: <numbers> | Unlink the number from its SFVoPI app first |
409 | Number(s) linked to an SFVoPI app (inactive); unlink them from the app first: <numbers> | The number still has an inactive SFVoPI app link. Unlink it from the app first |
409 | Number(s) already attached to another SF trunk: <numbers> | Detach the number from the other trunk first |
409 | Number(s) not in a serviceable state: <numbers> | The number is on hold or refunded. Email us |
404 | Number is not attached to this SF trunk | You tried to detach a number that is not on this trunk |
Linking a trunk number to an SFVoPI app fails the same way, with 409 and VoIP number is already attached to an SF trunk: <number>. Detach it from the trunk first.
Getting help
Email hello@superfone.in with SF Trunk in the subject and include:
- your trunk FQDN,
- the calling and called numbers,
- the date and time of the call, with time zone,
- the SIP response your PBX received, and
- the
Call-IDof the call, if you have it.
Next Steps
- Getting Started: codecs, methods and network settings
- Outbound calls: addressing and caller ID
- Inbound calls: attaching numbers and delivery
- FAQ: common questions