<div dir="ltr">Hello,<div> </div><div>I am trying to establish multiple 5G multiplex slices on a Telit FN990 modem running in QMI mode. These 5G slices represent multiple PDNs managed by ModemManager (via mmcli).</div><div> When using the "--test-multiplex-requested" option, the bearer setup fails with the following Netlink error: <pre><code>GDBus.Error:org.gtk.GDBus.UnmappedGError.Quark._g_2dio_2derror_2dquark.Code0: failed to create net link for device: failed to add link for device: Could not allocate link: Failed to add link with mux id 1: Netlink message with transaction 9 failed </code></pre> <hr> Environment: <ul> <li>Modem: Telit FN990A28 in QMI mode</li> <li>ModemManager: 1.22.0</li> <li>libqmi: 1.34.0-2</li> <li>libmbim: 1.30.0-2</li> <li>Kernel: 5.15.150</li> <li>OpenWrt: Based on 22.03 using netifd</li> </ul> <hr> Debug Logs During Bearer Connection: (PFA message_modem_debug) 2024-12-28T00:38:03.709 DEBUG daemon ModemManager[9676]: [1735346283.709521] [modem0/bearer1] connecting... 2024-12-28T00:38:03.709 NOTICE daemon ModemManager[9676]: [1735346283.709796] [modem0] state changed (registered -> connecting) 2024-12-28T00:38:03.709 DEBUG daemon ModemManager[9676]: [1735346283.709904] [modem0/bearer1] launching connection with QMI port (cdc-wdm0) and data port (wwan0) (multiplex requested) 2024-12-28T00:38:03.709 DEBUG daemon ModemManager[9676]: [1735346283.709916] [cdc-wdm0/qmi] bringing down data interface 'wwan0' 2024-12-28T00:38:03.710 DEBUG daemon ModemManager[9676]: [1735346283.710309] [cdc-wdm0/qmi] resetting expected kernel data format to 802.3 in data interface 'wwan0' 2024-12-28T00:38:03.897 WARN daemon ModemManager[9676]: [1735346283.897197] [modem0/bearer1] connection attempt #1 failed: failed to create net link for device: failed to add link for device: Could not allocate link: Failed to add link with mux id 1: Netlink message with transaction 1 failed 2024-12-28T00:38:03.898 NOTICE daemon netifd: CELL1 (19170): error: couldn't connect the modem: 'GDBus.Error:org.gtk.GDBus.UnmappedGError.Quark._g_2dio_2derror_2dquark.Code0: failed to create net link for device: failed to add link for device: Could not allocate link: Failed to add link with mux id 1: Netlink message with transaction 1 failed' <hr> Similar Issue Reported: This issue has been reported in the following GitLab issue: <a href="https://gitlab.freedesktop.org/mobile-broadband/ModemManager/-/issues/533">GitLab ModemManager Issue #533</a>, but I have not seen a resolution for it. Reference Links: <ul> <li><a href="https://lists.freedesktop.org/archives/modemmanager-devel/2022-March/009191.html">ModemManager Mailing List - March 2022</a></li></ul> Any assistance or suggestions on resolving this issue would be greatly appreciated. Thanks, Pradeep G </div><div> </div></div> This electronic communication and the information and any files transmitted with it, or attached to it, are confidential and are intended solely for the use of the individual or entity to whom it is addressed and may contain information that is confidential, legally privileged, protected by privacy laws, or otherwise restricted from disclosure to anyone else. If you are not the intended recipient or the person responsible for delivering the e-mail to the intended recipient, you are hereby notified that any use, copying, distributing, dissemination, forwarding, printing, or copying of this e-mail is strictly prohibited. If you received this e-mail in error, please return the e-mail to the sender, delete it from your computer, and destroy any printed copy of it.