outbound call sounds worse than inbound
# supporte
Enyedi Péter
04/07/2025, 12:33 PMI am using telnyx as a phone number provider, and my inbound voice quality is fine, but my outbound has much worse quality, it is very distorted, how can I help that?
v
Vapi Support Bot
04/07/2025, 12:35 PMHi there! Sorry to hear you're experiencing issues with your outbound call quality through Telnyx.
While I can't pinpoint exactly why your outbound calls sound worse than inbound calls in your specific setup, I can definitely help with several potential solutions to improve your outbound call quality.
Here are some things you can try to improve your outbound call quality with Telnyx:
### Telnyx-Specific Settings
1. Enable Telnyx's Built-in Denoiser - Telnyx has a built-in denoiser feature that can be enabled on their end, which can potentially solve voice quality issues. [According to our documentation](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1337367225384046634), this can make a significant difference.
2. Adjust Outbound Voice Profiles - In Telnyx, navigate to voice/outbound voice profiles to create a profile, name it, allow desired destinations, and assign the desired SIP trunk. [This can help optimize your call routing](https://docs.vapi.ai/advanced/sip/telnyx).
3. Country Selection for Outbound Calls - In the Outbound tab of Telnyx, select the country you'll be calling the most. It's recommended to create a separate SIP Trunk for each country you aim to make the most calls to for better quality. [This is mentioned in our Telnyx integration guide](https://docs.vapi.ai/advanced/sip/telnyx).
### Codec Settings
4. Check Codec Compatibility - Ensure that the codecs used by Vapi (PCMU/8000, PCMA/8000, opus/48000/2) are supported by your SIP endpoint. [According to our documentation](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1336713212233515089), codec incompatibility can cause quality issues.
Vapi Support Bot
04/07/2025, 12:35 PM5. Optimize Codec Selection - Consider the trade-offs between quality and bandwidth. PCMU and PCMA offer better quality but require higher bandwidth compared to G729. [Our documentation indicates](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1333444985353404558) that G729 has been tested with Telnyx.
### Network Configuration
6. Check Firewall and NAT Settings - Ensure your network allows SIP traffic and that firewalls or NATs are configured properly. [SIP ALG settings or other firewall configurations](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1334919245468799007) could be interfering with the SIP messages.
7. Optimize Network Connectivity - High network latency can cause delays in voice communication. Consider using a CDN with edge locations close to your users to reduce physical distance and network hops. [This can significantly improve call quality](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1336685825227755591).
### Additional Settings
8. Set Endpointing to 300 - [According to our documentation](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1338470163825033287), setting endpointing to 300 can improve voice quality.
9. Enable Background Noise Reduction - Enabling background denoising filters noise and background speech while the user is talking. [This can help with clarity](https://docs.vapi.ai/api-reference/assistants/create).
Would you like me to elaborate on any of these suggestions or provide more specific troubleshooting steps?
Sources:
- [Telnyx Built-in Denoiser](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1337367225384046634)
- [Telnyx Integration Guide](https://docs.vapi.ai/advanced/sip/telnyx)
- [Codec Compatibility](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1336713212233515089)
Vapi Support Bot
04/07/2025, 12:35 PM- [Codec Selection](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1333444985353404558)
- [Firewall Configuration](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1334919245468799007)
- [Network Optimization](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1336685825227755591)
- [Endpointing Settings](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1338470163825033287)
- [Background Noise Reduction](https://docs.vapi.ai/api-reference/assistants/create)
k
Kings_big💫
04/07/2025, 3:39 PMCan you send your call_id here ?
e
Enyedi Péter
04/07/2025, 3:40 PMyeah
Enyedi Péter
04/07/2025, 3:40 PM595dc38a-a161-467d-91e1-c8bbb5fb304c
Enyedi Péter
04/07/2025, 3:41 PMtried with your advice too, to use it with VAPI endpointing, but it didn't work
k
Kings_big💫
04/07/2025, 3:41 PMOoh I noticed you created two tickets??
e
Enyedi Péter
04/07/2025, 3:42 PMno it was another ticket, but commented another problem in there
k
Kings_big💫
04/07/2025, 3:42 PM@Sahil will assist you further, thanks for your patience
e
Enyedi Péter
04/07/2025, 3:42 PMthank you I would need the help as soon as possible.
s
Sahil
04/07/2025, 5:00 PMYou will need to check with the telynx team. The static noise is coming from telephony provider side.
k
Kings_big💫
04/07/2025, 5:39 PM@Enyedi Péter
s
Shubham Bajaj
04/07/2025, 10:28 PMMarking this ticket as Solved ✅