This tutorial explains how to setup and configure OpenWrt for using a USB 3g/UMTS-modem for WAN connection using the older and slower ppp protocol. Many modern and most LTE usb modems provide qmi, mbim, ncm, rndis protocol for connection instead of legacy ppp protocol, they are faster and better, overall recommended. For more information You may also want to checkout the multiwan_package package to use this simultaneously with other connections to the internet. Cellular mobile telephony can be intercepted very easily. Remember this is a wireless connection. Many mobile ISPs block certain or most ports. Port forwarding will probably not work as the traffic is blocked by the ISP's firewall. If you've got a Huawei E367 which will work, or a Huawei E585 which does not currently work, you may want to read the following tutorial which includes info on why you may not be able to get the on-board micro-SD card to function If you have the Leadtek FlashOFDM card Flarion from T-Mobile in Slovakia and the Asus WL-500g Premium, you may use the image on If you wish to get more information, or another distribution with the driver, please contact Accalio Some modem sticks provide an usb-ethernet-device Huawei “HiLink” - device numbers with 'h', but also other manufacturers like ZTE has such products MF823, MF831, ... In that case you should install usb-modeswitch package and follow usb tethering tutorial. Tethering will in most cases add an additional NAT layer. If you prefer to let OpenWRT care about dialing in, routing, NATting, firewalling or if your provider assigns you an external IPv4 which is most useful for setups, that need port forwarding, you will most likely want to set “modeswitch” your 3g/4g modem to act as a serial device. Serial device modes If a dongle in permanently configured for serial mode, it is advised not to install usb-modeswitch onto your router device. Modem sticks are commonly equipped with a flash space containing drivers and software and/or provide a slot for a micro-SD-card. These features like the 'NO-CD' feature can be configured in various ways. These configurations may be stored permanently. In that case a modeswitch will behave in an unpredictable way. A modem stick, that was previously configured as a modem will show up as serial devices typically /dev/ttyUSB0-2. A default setting in combination with modeswitch may additionally show the sd-card reader. See the Troubleshooting section in this document for further information. First install required packages If you are doing an offline installation, you might need some of these packages handy First install needed packages opkg update opkg install comgt kmod-usb-serial kmod-usb-serial-option kmod-usb-serial-wwan usb-modeswitch Now plug your USB Dongle to the USB port and restart the router. Check dmesg for USB Serial support registered for generic usbserial_generic 1-1 generic converter detected USB Serial support registered for generic usbserial_generic 1-1 generic converter detected usb 1-1 generic converter now attached to ttyUSB0 usbserial_generic 1-1 generic converter detected usb 1-1 generic converter now attached to ttyUSB1 ... usbcore registered new interface driver usbserial_generic usbserial USB Serial Driver core USB Serial support registered for GSM modem 1-port usbcore registered new interface driver option option Driver for GSM modems If above lines do not appear in dmesg, but instead you see something like scsi1 SCSI emulation for USB Mass Storage devices usb-storage device found at 4 usb-storage waiting for device to settle before scanning scsi 1000 CD-ROM Novatel Mass Storage PQ 0 ANSI 0 scsi 1000 Attached scsi generic sg1 type 5 usb-storage device scan complete then, depending on your modem, you have to switch device mode described below. If you can't see usbserial_generic go to usbserial_generic missing in dmesg The shown configuration replaces the WAN line, so no further changes are needed to the firewall/other configuration. Note that if you also want to use the WAN port, you have to define it as WAN2 in the configuration. If you define the 3g connection as WAN2, you have to do more changes to other parts, like firewall and so on. Edit your '/etc/config/network' file see network 3G section for more details config interface wan option ifname ppp0 on some carriers enable this line option pincode 1234 option device /dev/ttyUSB0 option apn option service umts option proto 3g Replace 'pincode' with the correct pincode of your SIM card. Note that a disabled pincode on the SIM card is problematic, please enable it. If you are connecting to a phone where the pincode has already been entered, there is no need for this. Replace 'device' with the correct USB port of your modem. On a phone this might for example be /dev/ttyACM0. Replace 'apn' with the correct APN of your 3g/umts provider. Note in case your APN also requires an username/password, you can configure this too, just add to the network configuration file option username yourusername option password yourpassword Replace 'username' and 'password' with the correct username/password you received from your 3g provider. You can also look for this information apn, username and password in the mobile-broadband-provider-info database from the Gnome project. For some providers, apparently it is necessary to add 'noipdefault' to 'pppd_options'. If logread shows that the connection was established and CHAP authentication was successful, but the connection was immediately dropped after, then try option 'pppd_options' 'noipdefault' If your provider supports PAP authentication only then you need to disable all other protocols via these added options option 'pppd_options' 'noipdefault refuse-chap refuse-mschap refuse-mschap-v2 refuse-eap' Now you have configured the network interface. Now we need to check if the default chatscript does work with your 3g provider or not. You can find it here '/etc/chatscripts/ it looks like this ABORT BUSY ABORT 'NO CARRIER' ABORT ERROR REPORT CONNECT TIMEOUT 12 "" "AT&F" OK "ATE1" OK 'AT+CGDCONT=1,"IP","$USE_APN"' ABORT 'NO CARRIER' TIMEOUT 15 OK "ATD*99***1" CONNECT ' ' If your modem needs a special AT command, your can add it to this file. You may have to edit the dial number of the ATD command to fit in with your provider's settings for example “*99” instead of “*99***11”. Just type on console 'ifup wan' Now check dmesg logread for successful connect pppd started by root, uid 0 abort on BUSY abort on ERROR report CONNECT timeout set to 12 seconds send AT&F^M expect OK AT&F^M^M OK - got it send ATE1^M expect OK ^M ATE1^M^M OK - got it send AT+CGDCONT=1,"IP"," abort on NO CARRIER timeout set to 15 seconds expect OK ^M AT+CGDCONT=1,"IP"," OK - got it send ATD*99***1^M expect CONNECT ^M ATD*99***1^M^M CONNECT - got it send ^M Serial connection established. Using interface 3g-wan Connect 3g-wan /dev/ttyUSB0 Could not determine remote IP address defaulting to local IP address remote IP address primary DNS address secondary DNS address adding wan 3g-wan to firewall zone wan That's it, now you should be connected. If you want an permanent connect from startup, add 'ifup wan' command to '/etc/ file. For troubleshooting or locating the best position for the USB Dongle, you can use gcom info -d /dev/ttyUSBx from the console. This tool will report signal strength, but also network registration and SIM status. If it returns a port-in-use error because your connection is already up, try gcom -d /dev/ttyUSBx where x represents a port number not used by the wan connection itself. gcom returns the signal quality in RSSI Received signal strength indication and in BER Bit error rate, reported in percent. A higher RSSI value represents a stronger signal - scale is from 0 to 99, where 1 is the lowest detectable signal and 31 a very good signal. Don't expect your signal to go all the way up to 99, though. If BER returns 99 it means not known or not detectable. If your 3G modem is a ZTE K3565-Z featuring a LED SSI indicator to show it's status Not Connected, GPRS, UMTS you may be mislead to believe, that a strong signal strength of 17 may be better, while you only get GPRS, but a value of 4 allows for UMTS access. This is owed to the circumstance, that the device may switch over to another cell. The only method to prevent a handover between a GPRS and an UMTS station during the process of optimizing, is to initiate the device to use 'UMTS only' in the first place. You can also add the AT command "" "AT+CSQ" to your chat script to check signal quality. Command return is “+CSQ ,” and looks like this in logread send AT+CSQ^M expect OK ^M AT+CSQ^M^M +CSQ 11,99^M ^M OK - got it If you have problems establishing a connection and multiple modem devices /dev/ttyUSB0, /dev/ttyUSB1, ... are present, try all of them. Some may not work at all while others seem to work at first, but will give a NO CARRIER during the connection process. /etc/ starts aiccu when the WAN connection is established. It seems however that, in the case of 3G connections, the start scripts are started just a bit too early and the start of aiccu fails. I have butchered the script a bit !/bin/sh [ "$ACTION" = "ifup" -a "$INTERFACE" = "wan" ] && /etc/ enabled && sleep 15; /etc/ restart Note that sixxs really frowns upon quick re-re-restarts of aiccu, it may get your account blocked for unjust use of resources. Be careful with these scripts. You can use many usb 3G dongles easily by using an active USB hub. Prepare for the next steps We assume you have at least one 3g dongle configured. You will need an active internet connection in order to install modules for 3g support. Check 3gdongle for more information. 1. Connect an active USB hub to the OpenWrt router. You need to assure, that the power supply will deliver sufficent power for all of your 3g dongles. A proper estimation is, that you will need 500+ mA per one 3g dongle. Remember that modem can slightly exceed its declared power consumption in HDSPA+ modes. Be generous and pick USB hub with some power source overhead. 2. Connect all 3g dongles and start. 3. Browse through logread to check if modems are properly recognized and /ttyUSB ports are assigned. 4. Usually a 3g modem has a few “modem ports” - one for connection and others are service types. Exeplum gratum A Huawei E1750 has three ports. The first in is a communication port and last is a service port. If you only have one modem, it will be recognized as /ttyUSB0, /ttyUSB1 and /ttyUSB2. You need to configure interface using /ttyUSB0 first one. A Huawei E372 has five ports, but similar to other Huawei devices, the communication port is the first one. 5. You need to configure interfaces. An example of “/etc/config/network” could look like this config 'interface' 'wan' option 'proto' '3g' option 'service' 'umts' option 'device' '/dev/ttyUSB0' option 'apn' 'internet' option 'pincode' '' option 'username' '' option 'password' '' Usually you need to provide an APN name in “option 'apn' 'Name-Of-APN-HERE'”. If your sim card is locked with a PIN, or if your porvider requires to use a username and/or pass, add it accordingly. 6. Check in log read next /ttyUSB[X] ports. In my case I have second modem starting with /ttyUSB3 previous one use /ttyUSB0 to /ttyUSB2 so second interface looks like this config 'interface' 'wan2' option 'proto' '3g' option 'service' 'umts' option 'maxwait' '0' option 'device' '/dev/ttyUSB3' option 'apn' 'internet' option 'pincode' '' option 'username' '' option 'password' '' 7. Remember to add second interface to the zone “wan” in the firewall's config file “/etc/config/firewall” it may differ in your case config 'zone' option 'name' 'wan' option 'input' 'REJECT' option 'output' 'ACCEPT' option 'forward' 'REJECT' option 'masq' '1' option 'mtu_fix' '1' option 'network' 'wan wan2' Look at last line - there is wan2 added. 8. Now you have both interfaces configured and they should work. 9. You can use both interfaces as a failover. This section needs a complete rewrite to fix spelling and grammar errors. loadbalncer - Note It seems multiwan isn't perfectly suited for 3G modems in terms of stability. Modems don't reconnect automatically by HealthMonitor. Also, after a manual modem restart, multiwan doesn't use the newly reattached interface until it's restarted. Configuration files for two 3G modems paired in multiwan Network default route to 0 and peerdns to 0 config 'interface' 'loopback' option 'ifname' 'lo' option 'proto' 'static' option 'ipaddr' ' option 'netmask' ' config 'interface' 'lan' option 'ifname' ' option 'type' 'bridge' option 'proto' 'static' option 'ipaddr' ' option 'netmask' ' config 'interface' 'wan' option 'proto' '3g' option 'service' 'umts' option 'device' '/dev/ttyUSB0' option 'apn' 'vpn' option 'pincode' '' option 'username' 'vpn' option 'password' 'vpn' option 'maxwait' '20' option 'defaultroute' '0' config 'interface' 'wan2' option 'proto' '3g' option 'service' 'umts' option 'device' '/dev/ttyUSB3' option 'apn' 'erainternet' option 'pincode' '' option 'username' 'erainternet' option 'password' 'erainternet' option 'maxwait' '10' option 'defaultroute' '0' config 'switch' option 'name' 'rtl8366s' option 'reset' '1' option 'enable_vlan' '1' option 'blinkrate' '2' config 'switch_vlan' option 'device' 'rtl8366s' option 'vlan' '1' option 'ports' '0 1 2 3 5t' config 'switch_port' option 'device' 'rtl8366s' option 'port' '1' option 'led' '6' config 'switch_port' option 'device' 'rtl8366s' option 'port' '2' option 'led' '9' config 'switch_port' option 'device' 'rtl8366s' option 'port' '5' option 'led' '2' Firewall - add second wan zones config 'defaults' option 'syn_flood' '1' option 'input' 'ACCEPT' option 'output' 'ACCEPT' option 'forward' 'REJECT' option 'drop_invalid' '1' config 'zone' option 'name' 'lan' option 'network' 'lan' option 'input' 'ACCEPT' option 'output' 'ACCEPT' option 'forward' 'REJECT' config 'zone' option 'name' 'wan' option 'input' 'REJECT' option 'output' 'ACCEPT' option 'forward' 'REJECT' option 'masq' '1' option 'mtu_fix' '1' option 'network' 'wan' config 'rule' option 'src' 'wan' option 'proto' 'udp' option 'dest_port' '68' option 'target' 'ACCEPT' option 'family' 'ipv4' config 'rule' option 'src' 'wan' option 'proto' 'icmp' option 'icmp_type' 'echo-request' option 'family' 'ipv4' option 'target' 'ACCEPT' config 'rule' option 'src' 'wan' option 'proto' 'icmp' list 'icmp_type' 'echo-request' list 'icmp_type' 'destination-unreachable' list 'icmp_type' 'packet-too-big' list 'icmp_type' 'time-exceeded' list 'icmp_type' 'bad-header' list 'icmp_type' 'unknown-header-type' list 'icmp_type' 'router-solicitation' list 'icmp_type' 'neighbour-solicitation' option 'limit' '1000/sec' option 'family' 'ipv6' option 'target' 'ACCEPT' config 'rule' option 'src' 'wan' option 'dest' '*' option 'proto' 'icmp' list 'icmp_type' 'echo-request' list 'icmp_type' 'destination-unreachable' list 'icmp_type' 'packet-too-big' list 'icmp_type' 'time-exceeded' list 'icmp_type' 'bad-header' list 'icmp_type' 'unknown-header-type' option 'limit' '1000/sec' option 'family' 'ipv6' option 'target' 'ACCEPT' config 'include' option 'path' '/etc/ config 'forwarding' option 'dest' 'wan' option 'src' 'lan' config 'rule' option 'target' 'ACCEPT' config 'zone' option 'name' 'wan2' option 'forward' 'REJECT' option 'output' 'ACCEPT' option 'network' 'wan2' option 'input' 'REJECT' option 'masq' '1' option 'mtu_fix' '1' config 'forwarding' option 'dest' 'wan2' option 'src' 'lan' Multiwan - Additionally add option 'health_monitor' 'serial' at the beggining to help healthmonitor check for dropped ppp interface Proposed by Jolouis. config 'multiwan' 'config' option 'health_monitor' 'serial' option 'default_route' 'fastbalancer' option 'debug' '1' config 'interface' 'wan' option 'health_fail_retries' '3' option 'health_recovery_retries' '5' option 'failover_to' 'fastbalancer' option 'timeout' '10' option 'dns' ' option 'weight' '10' option 'health_interval' '120' option 'icmp_hosts' 'gateway' config 'interface' 'wan2' option 'timeout' '3' option 'health_fail_retries' '3' option 'health_recovery_retries' '5' option 'failover_to' 'fastbalancer' option 'dns' ' option 'weight' '10' option 'health_interval' '120' option 'icmp_hosts' 'gateway' config 'mwanfw' option 'src' ' option 'wanrule' 'wan2' config 'mwanfw' option 'wanrule' 'fastbalancer' I had issues with auto reconnecting modems so I've modified script for checking if modems are up. This script checks modems separately. I've based this on a great tutorial found at Create script cat /bin/ !/bin/sh if ! ping -q -c 1 -W 10 -I 3g-wan > /dev/null; then ifup wan; sleep 5; /etc/ restart & fi if ! ping -q -c 1 -W 10 -I 3g-wan2 > /dev/null; then ifup wan2; sleep 5; /etc/ restart & fi EOF chmod 755 /bin/ Create CRON job echo "*/2 * * * * /bin/ >> /etc/crontabs/root /etc/ restart This will ping through two wans 3g-wan and 3g-wan2 and restarts the interface in case of no replies. Additionally, It will wait 5 seconds and force a multiwan restart as it seems wouldn't recognize the new wan interfaces. Restart of multiwan should take care of this situation. Luci has supported 3G configuration. Be sure to have luci and luci-proto-3g installed. If you want to do multiwan configuration, make sure that luci-apps-multiwan is installed and optionally, luci-app-mwan3. To create a new 3g connection, go to Luci web interface. Navigate to Network ⇒ interfaces. Click on Add new interface button. Give a simple name to the interface, for example 3g and choose UMTS/GPRS/EVDO as its protocol. Here is basic configuration to get the connection working. General Setup Protocol UMTS/GPRS/EVDO Modem device /dev/ttyUSB0 Service type UMTS only You may prefer UMTS/GPRS if you wish APN internet Not needed for CDMA/EVDO PIN 1234 Leave it blank if you don't use pin PAP/CHAP username PAP/CHAP password Advanced Settings leave them as default Firewall Settings Create / Assign firewall zone wan If you want to enable IPv6 on 3G connection, make sure that your dongle supports PDPv61 and your 3G provider is providing IPv6 service. To enable IPv6 negotiation on the PPP link, issue the following command. uci set uci commit Be sure to replace 3g with the correct name of 3G interface. In addition, be sure to edit file /etc/chatscripts/ for PDPv6 configuration as currently there is no UCI entry for PDPv6. ABORT BUSY ABORT 'NO CARRIER' ABORT ERROR REPORT CONNECT TIMEOUT 10 "" "AT&F" OK "ATE1" OK 'AT+CGDCONT=1,"IPV6","$USE_APN"' SAY "Calling UMTS/GPRS" TIMEOUT 30 OK "ATD$DIALNUMBER" CONNECT ' ' You may use the following chatscript for PDPv4v6 configuration. Make sure that your dongle supports PDv4v62 before attempting to modify the chatscript. ABORT BUSY ABORT 'NO CARRIER' ABORT ERROR REPORT CONNECT TIMEOUT 10 "" "AT&F" OK "ATE1" OK 'AT+CGDCONT=1,"IPV4V6","$USE_APN"' SAY "Calling UMTS/GPRS" TIMEOUT 30 OK "ATD$DIALNUMBER" CONNECT ' ' If you are using Luci, be sure to check Enable IPv6 negotiation on the PPP link and optionally Use builtin IPv6-management on the Advanced settings section of the 3G interface configuration page. Also, be sure to modify /etc/chatscripts/ file for PDPv6 as explained above. Of course you can use other methods to obtain IPv6 instead of relying on PPP negotiation. See IPv6 for more explanation. WARNING - this will deactivate WEB-GUI access on these devices!!! You need to know howto submit AT commands to a modem in order to restore the GUI. Huawei ZTE Huawei ZTE AT+ZCDRUN=9 AT+ZCDRUN=F Sources 34 General information on modeswitching Modeswitching issues can occur especially on devices, in fallback modes Huawei. It is advisable to install usbutils opkg update && opkg install usbutils You can look for the usb ids from lsusb in /etc/ to see what modeswitch actions are being taken. If you prefer to permantently switch a modem to serial/fallback mode, see and take actions to deactivate the json-based modeswitch for that specific product id. The following section will go into details on how to do this for the ancient E220. The following sections for MA260 explain, how such workarounds have looked like before the introduction of OpenWRT Chaos Calmer. It may in some cases be easier to delete the file /etc/ with a custom modeswitch file, if necessary. A previously configured serial modem, that is unknown to the kernel can be manually associated with it's driver by assigning it the manufacturer and product id as shown by lsusb as follows for E220 in fallback mode echo '12d1 1001 ff' > /sys/bus/usb-serial/drivers/option1/new_id Huawei E220/Chaos Calmer If you encounter problems with an undetected Huawei E220, you can try the following - this resets the E220 to its factory defaults, so it can again be handled by the new JSON-based modeswitch. This will reenable the CD-ROM Mode. 1. Make the modem work once, by manually telling the kernel to use generic option drivers. echo '12d1 1003 ff' > /sys/bus/usb-serial/drivers/generic/new_id 2. Shutdown WWAN necessary only if WWAN was previously configured ifdown WWAN 3. Modes of the E220 Modem + PC UI echo "AT^U2DIAG=0" >/dev/ttyUSB0 Modem + CD echo "AT^U2DIAG=1" >/dev/ttyUSB0 4. Reboot reboot If you can't see usbserial_generic in dmesg, try loading the usbserial module and are Vendor and Product ID of your device rmmod usbserial optional insmod /lib/modules/`uname -r`/ vendor=0x product=0x Alternatively, you can also use option GSM driver on your dongle. Option driver is more reliable, as it can distinguish between serial port and storage port. insmod option skip this if option driver is loaded already echo ' ff' > /sys/bus/usb-serial/drivers/option1/new_id To automate the process of attaching option serial driver on boot, just edit /etc/ and place echo ' ff' > /sys/bus/usb-serial/drivers/option1/new_id before the exit code exit 0 Adding the above to hotplug instead of You can easily integrate this into hotplug in the following way - in this example we will use a fictional “3G Dongie HSPA+” Dongle Create and edit the file /etc/ !/bin/sh ... DONGIEHSPAPLUS_PRODID="0815/9000/0" if [ "${PRODUCT}" = "${DONGIEHSPAPLUS_PRODID}" ]; then if [ "${ACTION}" = "add" ]; then ... echo '0815 9000 ff' > /sys/bus/usb-serial/drivers/option1/new_id ... If your modem's switched product id is 08159000, the above will work. So for your modem you will have to replace all appearances of the variable DONGIEHSPAPLUS_PRODID and all appearance of “0815” and “9000” in the above example with your matching product's name, vendor and product id. Check dmesg again for usbcore registered new interface driver usbserial USB Serial support registered for generic usbserial_generic generic converter detected usb generic converter now attached to ttyUSB0 usbserial_generic generic converter detected usb generic converter now attached to ttyUSB1 usbcore registered new interface driver usbserial_generic usbserial USB Serial Driver core Also check kernel USB debug for loaded drivers rootOpenWrt~ cat /sys/kernel/debug/usb/devices T Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev= 3 Spd=480 MxCh= 0 D Ver= Cls=00>ifc Sub=00 Prot=00 MxPS=64 Cfgs= 1 P Vendor=1c9e ProdID=9800 Rev= S Manufacturer=USB Modem S Product=USB Modem S SerialNumber=1234567890ABCDEF C* Ifs= 4 Cfg= 1 Atr=e0 MxPwr=500mA I* If= 0 Alt= 0 EPs= 2 Cls=ffvend. Sub=ff Prot=ff Driver=option E Ad=81I Atr=02Bulk MxPS= 512 Ivl=0ms E Ad=01O Atr=02Bulk MxPS= 512 Ivl=4ms I* If= 1 Alt= 0 EPs= 3 Cls=ffvend. Sub=ff Prot=ff Driver=option E Ad=82I Atr=03Int. MxPS= 64 Ivl=2ms E Ad=83I Atr=02Bulk MxPS= 512 Ivl=0ms E Ad=02O Atr=02Bulk MxPS= 512 Ivl=4ms I* If= 2 Alt= 0 EPs= 2 Cls=ffvend. Sub=ff Prot=ff Driver=option E Ad=84I Atr=02Bulk MxPS= 512 Ivl=0ms E Ad=03O Atr=02Bulk MxPS= 512 Ivl=4ms I* If= 3 Alt= 0 EPs= 2 Cls=08stor. Sub=06 Prot=50 Driver=usb-storage E Ad=04O Atr=02Bulk MxPS= 512 Ivl=0ms E Ad=85I Atr=02Bulk MxPS= 512 Ivl=0ms

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