Session interval too small

Occasional Contributor

Session interval too small


In our company we have several endpoints, all of them registered to a Cisco Videoconference Server (VCS).

When we call from our VSX7000 via SIP, a new entry appears in the VCS call history log: "422 Session interval too small". It all seems to work fine at first, but after about 13 minutes (not exactly), the call is disconnected.


I've looked into it and I've seen it has something to do with the RFC 4028, but I don't know how to solve it.


I could adjust two parameters in the VCS SIP configuration. These are:

- Session refresh interval (set to default 1800 s).

- Minimum session refresh interval (set to default 500 s).


I have not found anything about it in the VSX7000 configuration.


Can anyone help me?


Message 1 of 3
Polycom Employee & Community Manager

Re: Session interval too small

Hello Victor77,

welcome to the Polycom Community.

It is always useful to include the currently used Software version as issues experienced may already be addressed in a newer release.

Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.

Best Regards

Steffen Baier

Polycom Global Services


If official support is required please check how to phone or open a case here

The title Poly Employee & Community Manager is a community setting and does not reflect my role. I am just a simple volunteer in the community like everybody else. All posts and words are my own & do not represent the views of Employer.


Notice: This community forum is not an official Poly support resource, thus responses from Poly employees, partners, and customers alike are best-effort in attempts to share learned knowledge. If you need immediate and/or official assistance please open a service ticket through your proper support channels.
Please also ensure you always check the VoIP , Video Endpoint , Skype for Business , PSTN or RPM FAQ's
Message 2 of 3
Occasional Contributor

Re: Session interval too small


You're right. Here you have our VSX7000A software release: 9.0.5


I hope someone can help me.


Message 3 of 3