Call forwarding not working — troubleshooting guide
Fix missed or incorrectly forwarded calls in SparkTG. Covers missing country codes, wrong trigger conditions, SIP registration failures, and DND restrictions.
Call forwarding failures generally fall into two buckets: the forward was never triggered (routing logic issue), or it was triggered but the destination didn't answer (termination issue). This guide covers both.
Check the forwarding configuration
- 1
Verify the destination number
Dashboard → Numbers → your number → Forwarding Settings. Confirm the destination includes the country code (e.g., +91 for India). Missing the +91 prefix is the #1 cause of forward failures.
- 2
Check forward trigger conditions
Forwarding can be set to Always, On No Answer (after N seconds), On Busy, or On Unreachable. If set to On No Answer but the agent's SIP client is offline, the system treats it as Unreachable — a different condition. Set the correct trigger.
- 3
Test with a different destination
Temporarily change the forwarding destination to a personal mobile number and place a test call. If it now connects, the original destination number has an issue (switched off, DND, etc.).
SIP forwarding issues
- SIP client must be registered (green dot in your softphone app). Unregistered SIP extensions will never receive forwarded calls.
- Check SIP credentials haven't changed — go to Settings → SIP Accounts and verify the username/password match what's entered in your softphone.
- Firewall blocking SIP? Ensure UDP port 5060 and RTP ports 10000–20000 are open. Many corporate networks block these.
Mobile number forwarding limitations
Forwarding to mobile numbers registered under DND (Do Not Disturb) with TRAI will fail silently. Use a landline or SIP extension as the forwarding destination for production setups.
Check Reports → Call Logs for the exact SIP response code on failed forwards. Code 486 = destination busy, 480 = temporarily unavailable, 404 = number not found.
Frequently asked questions
Why is my call forwarding working sometimes but not always?
Do I need to include +91 when setting a forwarding number in SparkTG?
Why does my SIP extension not receive forwarded calls?
Can I forward calls to a mobile number registered under DND?
How do I find the exact error code for a failed forward in SparkTG?
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