<html><head></head><body><div style="color:#000; background-color:#fff; font-family:Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:13px"><div id="yui_3_16_0_ym19_1_1547217632084_107078"><span>Yeah, I had to change a lot of things up.</span></div><div id="yui_3_16_0_ym19_1_1547217632084_107079"><span><br></span></div><div id="yui_3_16_0_ym19_1_1547217632084_107082"><span id="yui_3_16_0_ym19_1_1547217632084_107081">When moving, the Sierra modem may switch bands, change IP addresses, go through dead zones, or through tower handoffs. The Sierra stays up -- if you use minicom or some other comm port read/writer on the AT port (/dev/ttyUSB2 for me), you can do:</span></div><div id="yui_3_16_0_ym19_1_1547217632084_107085"><span><br></span></div><div dir="ltr" id="yui_3_16_0_ym19_1_1547217632084_107090"><span id="yui_3_16_0_ym19_1_1547217632084_107236">at!gstatus? ---to see the connection status</span></div><div dir="ltr" id="yui_3_16_0_ym19_1_1547217632084_106865"><span id="yui_3_16_0_ym19_1_1547217632084_106867">at+cgcontrdp -- to see the IP addresses <br></span></div><div dir="ltr" id="yui_3_16_0_ym19_1_1547217632084_106863"><span><br></span></div><div dir="ltr" id="yui_3_16_0_ym19_1_1547217632084_106861"><span id="yui_3_16_0_ym19_1_1547217632084_106860">There are two sides to the LTE session, the Sierra -> Carrier and the Sierra -> OpenWRT/Linux. Using those AT commands, you can see the Sierra recovers from each of the above events. However, the Sierra -> Openwrt network session usually does not recover. It may have the old IP or gateway in the wwan interface, or even if it keeps the same IP, sometimes the link just breaks and needs to be reestablished depending on the size of the dead zone you went through.</span></div><div dir="ltr" id="yui_3_16_0_ym19_1_1547217632084_106858"><span><br></span></div><div dir="ltr" id="yui_3_16_0_ym19_1_1547217632084_106856">Aleksander said earlier in this thread that MM doesn't handle the reconnect of the Sierra->Openwrt side yet.</div><div dir="ltr" id="yui_3_16_0_ym19_1_1547217632084_106856"><br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1547217632084_106856">So, I ended up moving off of MM, checking connection status with AT commands, then setting up the IP link with a script. Once you get the IP/Gateway with 'uqmi --get-current-settings', you can use:</div><div dir="ltr" id="yui_3_16_0_ym19_1_1547217632084_106856">ip addr -- delete the old IP</div><div dir="ltr" id="yui_3_16_0_ym19_1_1547217632084_106856">ip addr -- add the new ip</div><div dir="ltr" id="yui_3_16_0_ym19_1_1547217632084_106856">route del default gw old.old.old.old</div><div dir="ltr" id="yui_3_16_0_ym19_1_1547217632084_106856">route add default gw xx.xx.xx.xx </div><div class="qtdSeparateBR" id="yui_3_16_0_ym19_1_1547217632084_106855"><br></div><div class="qtdSeparateBR" id="yui_3_16_0_ym19_1_1547217632084_106855" dir="ltr">You may or may not need to do an ifup wwan, and you have to make sure that /sys/class/net/wwan0/qmi/raw_ip is set to Y, or no data will go through.</div><div class="qtdSeparateBR" id="yui_3_16_0_ym19_1_1547217632084_106855" dir="ltr"><br></div><div class="qtdSeparateBR" id="yui_3_16_0_ym19_1_1547217632084_106855" dir="ltr">It's really tricky, I've been banging my head on it for a couple weeks, but I'm almost stable now. I just have some issues with Sierra AT command settings for different carriers to deal with.</div><div class="qtdSeparateBR" id="yui_3_16_0_ym19_1_1547217632084_106855" dir="ltr"><br></div><div class="qtdSeparateBR" id="yui_3_16_0_ym19_1_1547217632084_106855"><br></div><div class="qtdSeparateBR" id="yui_3_16_0_ym19_1_1547217632084_106855"><br><br></div><div class="yahoo_quoted" id="yui_3_16_0_ym19_1_1547217632084_106711" style="display: block;"> <div style="font-family: Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 13px;" id="yui_3_16_0_ym19_1_1547217632084_106710"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;" id="yui_3_16_0_ym19_1_1547217632084_106709"> <div dir="ltr" id="yui_3_16_0_ym19_1_1547217632084_106708"> <font size="2" face="Arial" id="yui_3_16_0_ym19_1_1547217632084_106719"> <hr size="1" id="yui_3_16_0_ym19_1_1547217632084_106853"> <b><span style="font-weight:bold;">From:</span></b> Nick <mips171@icloud.com><br> <b><span style="font-weight: bold;">To:</span></b> Peter Krause <peter@uringme.com> <br><b><span style="font-weight: bold;">Cc:</span></b> ModemManager <modemmanager-devel@lists.freedesktop.org><br> <b><span style="font-weight: bold;">Sent:</span></b> Sunday, January 13, 2019 10:44 PM<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: OpenWRT Sierra EM7455 drops connection while driving<br> </font> </div> <div class="y_msg_container" id="yui_3_16_0_ym19_1_1547217632084_106713"><br><div dir="ltr" id="yui_3_16_0_ym19_1_1547217632084_106717">Hey Peter,<br clear="none"><br clear="none">Did you ever make any progress on this? I think I am seeing the same thing over here.<br clear="none"><br clear="none">Best,<br clear="none">Nicholas</div><br><br></div> </div> </div> </div></div></body></html>