From: Martin Xu <martin.xu(a)intel.com&gt; [PATCH 1/2] PPP: Fix Trasmit ACCM and Receive ACCM setting error according to RFC 1662 section 7.2, looks like oFono has set receive and transmit ACCM wrongly. normally the two ACCM are both set as 0x00000000, and the issue will not be found. Once the they are different, oFono will run to error. [PATCH 2/2] Inform Huawei modem using ACCM 0xffffffff to trasmit package. Using my Huawei modem (EM770W) if set ACCM as 0x00000000, the RXJ- event will happend, and PPP link down, when IP package is transmited for a while. If I set ACCM as 0xffffffff, the RXJ- event never happen, and the modem can work quite stable. I tested the modem at China Unicom networks. Not sure whether the issue is specific to specific modem. If it is the case, ofono may let user to set the ACCM to specific modem. gatchat/ppp_lcp.c | 15 ++++++++++++--- 1 files changed, 12 insertions(+), 3 deletions(-) -- 1.7.2.2