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- HP Community
- Poly Phones
- Desk and IP Conference Phones
- CCX 440, 500 and E100 sip payload type fixed at 121

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06-17-2025 08:43 AM
Hi. We've hit an issue with a number of Poly phones: CCX440, CCX500 and E100.
A company that's providing the sip account that's being used has told me the issue is with the phones and their Freeswitch PBX.
When using Opus, the payload type appears to be fixed at 121, whereas Freeswitch rightly uses dynamic payload type for Opus. As a result of the mismatch, the audio fails, as Freeswitch is expecting the dynamically assigned payload type, and attempts to fall back to a default codec.
Steps to reproduce...
1. Remove all codecs from CCX phone's priority list, except for Opus.
2. Make a call to the CCX phone, from another SIP client via Freeswitch.
3. Answer the call on the CCX phone.
4. Call connects with silence, and Freeswitch log reports "alternate payload received (received 121)" and "Could not change to payload type 121".
All phones are using the latest versions of software and the problem replicates on each device. They've all been reset to factory settings and the problems still replicate.
Thanks in anticipation of a fix or workaround that we can set in the phone's config.
Solved! Go to Solution.
Accepted Solutions
06-17-2025 08:47 AM
Hello @Nick8718 ,
Welcome to the HP community.
Unfortunately, your post does not contain the currently used Software version for the HP Poly product in use.
This is important, especially in the future, when someone finds this post in days, months, or years.
Please do not simply edit the original post but reply with the versions.
In the FAQ or the Read 1st section, we remind users why this is important.
In addition are you Kevin or Nick ?
Duplicate post >here<
If no other volunteers reply, I suggest you contact our Support organization in your region. Details are in my Signature.
Best regards
Steffen Baier
Notice: I am an HP Poly employee but all replies within the community are done as a volunteer outside of my day role. This community forum is not an official HP Poly support resource, thus responses from HP Poly employees, partners, and customers alike are best-effort in attempts to share learned knowledge.
If you need immediate and/or official assistance for former Poly\Plantronics\Polycom please open a service ticket through your support channels
For HP products please check HP Support.
Please also ensure you always check the General VoIP , Video Endpoint , UC Platform (Microsoft) , PSTN
06-17-2025 08:47 AM
Hello @Nick8718 ,
Welcome to the HP community.
Unfortunately, your post does not contain the currently used Software version for the HP Poly product in use.
This is important, especially in the future, when someone finds this post in days, months, or years.
Please do not simply edit the original post but reply with the versions.
In the FAQ or the Read 1st section, we remind users why this is important.
In addition are you Kevin or Nick ?
Duplicate post >here<
If no other volunteers reply, I suggest you contact our Support organization in your region. Details are in my Signature.
Best regards
Steffen Baier
Notice: I am an HP Poly employee but all replies within the community are done as a volunteer outside of my day role. This community forum is not an official HP Poly support resource, thus responses from HP Poly employees, partners, and customers alike are best-effort in attempts to share learned knowledge.
If you need immediate and/or official assistance for former Poly\Plantronics\Polycom please open a service ticket through your support channels
For HP products please check HP Support.
Please also ensure you always check the General VoIP , Video Endpoint , UC Platform (Microsoft) , PSTN
06-17-2025 09:14 AM
Hi. We've hit an issue trying to use the Poly CCX400 and e100 with a Freeswitch PBX.
When using Opus, the payload type appears to be fixed at 121, whereas Freeswitch rightly uses dynamic payload type for Opus. As a result of the mismatch, the audio fails, as Freeswitch is expecting the dynamically assigned payload type, and attempts to fall back to a default codec.
Steps to reproduce...
1. Remove all codecs from CCX phone's priority list, except for Opus.
2. Make a call to the CCX phone, from another SIP client via Freeswitch.
3. Answer the call on the CCX phone.
4. Call connects with silence, and Freeswitch log reports "alternate payload received (received 121)" and "Could not change to payload type 121".
Software versions:
CCx400 running 9.1.1.0258
e100 running 8.2.3.0844
Thanks in anticipation of a fix or workaround that we can set in the phone's config.
06-17-2025 09:20 AM
Hello @Nick8718 ,
This is a peer to peer end user forum, not a support platform. All users are volunteers.
I suggest you contact our Support organization in your region. Details are in my Signature.
Best Regards
Steffen Baier
Notice: I am an HP Poly employee but all replies within the community are done as a volunteer outside of my day role. This community forum is not an official HP Poly support resource, thus responses from HP Poly employees, partners, and customers alike are best-effort in attempts to share learned knowledge.
If you need immediate and/or official assistance for former Poly\Plantronics\Polycom please open a service ticket through your support channels
For HP products please check HP Support.
Please also ensure you always check the General VoIP , Video Endpoint , UC Platform (Microsoft) , PSTN