M900: HTTP requests fail after some days uptime

At one of our client sites, M900 fails to update phone books, provisioning and download firmware updates after some days of uptime.

This error is shown in the logs:

2024-10-17 07:34:19.370-ERROR     [ GFT: ERROR - HTTPC_CONN_CREATE_CFM - Connection handle NULL ]

According to wireshark (using a mirror port or watching the internet gateway), the M900 will make no attempt at creating an HTTP connection when trying to manually reprovision or download an XML phonebook. A reboot fixes this but it works for only a few hours or a few days at most.

This is especially bad because if users update their account passwords, SIP registration fails. Usually, every few hours we pull provisioning data but the M900 eventually fails to create any new HTTP connection. Accordingly, neither phonebook updates are pulled from the PBX.

Model: M900

Base firmware: HSV740B104