Intro

The router is based on Mediatek MT7621 dual core SoC clocked at 880MHz with 16MiB SPI Flash chip and 512MiB DDR3 RAM chip. There are two MT7662E wireless chipsets and ASMedia ASM1062 SATA controller soldered onboard and connected via PCI lanes.

Motherboard of WG2626

This router can be purchased from AliExpress for 80USD, bulk orders from Alibaba should decrease item price considerably.

Flashing OpenWrt

The device comes already with OpenWrt albeit an older version. Gain access to command line and use following to update the firmware.

Older OpenWrt firmware, 3.18.x kernel, 3G works, illegal instruction and core dumps under high load, poor SATA throughput:

cd /tmp
wget http://downloads.openwrt.org/chaos_calmer/15.05.1/ramips/mt7621/openwrt-15.05.1-ramips-mt7621-zbt-wg2626-squashfs-sysupgrade.bin
sysupgrade openwrt-15.05.1-ramips-mt7621-zbt-wg2626-squashfs-sysupgrade.bin

Newer OpenWrt firmware, 4.4.x kernel, QMI based 3G cards fail, old school USB-to-serial based 3G cards work, installing microSD card support crashes router:

cd /tmp
wget http://downloads.openwrt.org/snapshots/trunk/ramips/mt7621/openwrt-ramips-mt7621-zbt-wg2626-squashfs-sysupgrade.bin
sysupgrade openwrt-ramips-mt7621-zbt-wg2626-squashfs-sysupgrade.bin

LEDE based firmware, 4.4.x kernel, QMI untested, old school 3G works, microSD card support unsable, SATA performance okay (50MB/s):

cd /tmp
http://downloads.lede-project.org/snapshots/targets/ramips/mt7621/lede-ramips-mt7621-zbt-wg2626-squashfs-sysupgrade.bin
sysupgrade lede-ramips-mt7621-zbt-wg2626-squashfs-sysupgrade.bin

Software packages

Once router is up and running with OpenWrt update package lists:

opkg update

Install software packages:

opkg install comgt fdisk htop  kmod-atm kmod-mii kmod-usb-acm kmod-usb-atm kmod-usb-net kmod-usb-net-qmi-wwan kmod-usb-serial kmod-usb-serial-option kmod-usb-serial-wwan kmod-usb-wdm kmod-usb2 kmod-usb3 luci mc nano usbutils pciutils

For 3G/LTE support:

opkg install luci-proto-3g luci-proto-ppp luci-proto-qmi ppp uclient-fetch uqmi usb-modeswitch wwan

opkg install luci-proto-qmi_git-17.130.58552-d04f667-1_all.ipk

If you don't have ethernet connectivity, on your laptop:

wget http://downloads.lede-project.org/releases/17.01.1/targets/ramips/mt7621/packages/kmod-usb-net-qmi-wwan_4.4.61-1_mipsel_24kc.ipk
wget http://downloads.lede-project.org/releases/17.01.1/targets/ramips/mt7621/packages/uqmi_2016-12-19-8ceeab69-1_mipsel_24kc.ipk
wget http://downloads.openwrt.org/snapshots/trunk/ramips/mt7620/packages/luci/luci-proto-qmi_git-17.130.58552-d04f667-1_all.ipk
wget http://downloads.lede-project.org/releases/17.01.1/targets/ramips/mt7621/packages/kmod-usb-wdm_4.4.61-1_mipsel_24kc.ipk
wget http://downloads.lede-project.org/releases/17.01.1/targets/ramips/mt7621/packages/kmod-usb-net_4.4.61-1_mipsel_24kc.ipk
scp *.ipk root@192.168.1.1:/tmp/
ssh root@192.168.1.1 opkg install /tmp/*.ipk

For fileserver and DLNA:

opkg install luci-app-samba minidlna

For storage in general:

opkg install kmod-scsi-generic blkid block-mount kmod-fs-btrfs kmod-fs-ext4 kmod-fs-vfat btrfs-progs

For USB storage:

opkg install kmod-usb-storage kmod-usb-storage-extras

For SATA:

opkg install kmod-ata-core kmod-ata-ahci

For microSD card support:

opkg install kmod-sdhci-mt7620

For OpenVPN:

opkg install openvpn-openssl luci-app-openvpn

Configuring 3G

Insert 3G card to mini PCI express, attach antennas and insert SIM card to the slot underneath the mini PCI express slot. In this case Ericsson F3507G Mobile Broadband Module salvaged from an old Thinkpad was used. Append following to /etc/config/network, adjust apn accordingly and reboot the box:

config interface 'wwan'
        option proto '3g'
        option device '/dev/ttyACM0'
        option apn 'internet.tele2.ee'
        option delegate '0'
        option ipv6 '0'
        option service 'umts_only'
        option pppd_options 'noipdefault'
        option dialnumber '*99#'

Summary

Mediatek support in mainline kernel needs still some time to mature but otherwise Mediatek based devices look promising alternative to Qualcomm/Atheros.