Etisalat S3

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OEM: Sercomm S3

Etisalat S3 is a wireless router based on the MT7621 platform with USB 3.0 port.

Etisalat S3

ModelVersionSoCCPU MHzCPU CoresFlash MBRAM MBWLAN HardwareWLAN2.4WLAN5.0100M portsGbit portsModemUSB
S3MediaTek MT7621A8802128NAND256MediaTek MT7603EN, MediaTek MT7615Nb/g/na/n/ac-5-1x 3.0

1. Login to the router web interface under admin account

2. Navigate to Settings → Configuration → Save to Computer

3. Decode the configuration. For example, using tool (A tool for decoding and encoding Sercomm configs - -u configurationBackup.cfg

4. Open configurationBackup.xml and find the following line:

<PARAMETER name="Password" type="string" value="<your router serial is here>" writable="1" encryption="1" password="1"/>

5. Insert the following line after and save:

<PARAMETER name="Enable" type="boolean" value="1" writable="1" encryption="0"/>

6. Encode the configuration. For example, using tool: -p configurationBackup.xml

7. Upload the changed configuration (configurationBackup_changed.cfg) to the router

8. Login to the router web interface (SuperUser:ETxxxxxxxxxx, where ETxxxxxxxxxx is the serial number from the backplate label)

9. Navigate to Settings → Access Control → Allow SSH (& Press apply)

10. Connect to the router using SSH shell under SuperUser account

11. Run in SSH shell:


12. Make a mtd backup (optional, see related section)

13. Change bootflag to Sercomm1 and reboot:

printf 1 | dd bs=1 seek=7 count=1 of=/dev/mtdblock3

14. Login to the router web interface under admin account

15. Remove dots from the OpenWrt factory image filename

16. Update firmware via web using OpenWrt factory image

It's recommended to make a mtd backup before you start:

1. Set up a tftp server (e.g. tftpd64 for windows)

2. Connect to a router using SSH shell and run the following commands:

cd /tmp
for i in 0 1 2 3 4 5 6 7 8 9 10; do nanddump -f mtd$i /dev/mtd$i; \
tftp -l mtd$i -p; md5sum mtd$i >> mtd.md5; rm mtd$i; done
tftp -l mtd.md5 -p

1. Change the bootflag to Sercomm1 in OpenWrt CLI and then reboot:

printf 1 | dd bs=1 seek=7 count=1 of=/dev/mtdblock3

2. Optional: Update with any stock (Etisalat S3) firmware if you want to overwrite OpenWrt in Slot 0 completely.

FIXME Find out flash layout, then add the flash layout table here (copy, paste, modify the example).

Please check out the article Flash layout. It contains examples and explanations that describe how to document the flash layout.

See Installation section

Not applicable


  • Browse to LuCI Upgrade URL
  • Upload image file for sysupgrade to LuCI
  • Wait for reboot

If you don't have a GUI (LuCI) available, you can alternatively upgrade via the command line. There is a command line method for upgrading:

  • sysupgrade

Note: It is important that you put the firmware image into the ramdisk (/tmp) before you start flashing.


  • Login as root via SSH on, copy images to /tmp using SCP and then enter the following commands:
cd /tmp
sysupgrade /tmp/sysupgrade.bin

1. Compile sercomm-recovery under the Linux:

git clone

2. Connect the router with a cable and run sercomm-recovery:

sudo ./sercomm-recovery enp0s3 recovery_etisalat_s3.bin

where enp0s3 - network interface connected the router, ifconfig - list on available network interfaces

Basic configuration After flashing, proceed with this.
Set up your Internet connection, configure wireless, configure USB port, etc.

The default network configuration is:

Interface Name Description Default configuration
br-lan LAN & WiFi
lan1-4 LAN ports (1-4) br-lan
wan WAN port DHCP
Port Switch port
Internet (WAN) wan
LAN 1 lan1
LAN 2 lan2
LAN 3 lan3
LAN 4 lan4

hardware.button on howto use and configure the hardware button(s). Here, we merely name the buttons, so we can use them in the above Howto.

The Etisalat S3 has the following buttons:

Reset reset
WPS wps
Brand Etisalat
Model S3
Device Type WiFi Router
Availability unknown 2022
Comments - general
OpenWrt Support
Supported Since Commit;a=commit;h=0ec8d991c24ab18e79bbbab279d0641b81161ca4
Supported Since Release
Supported Current Release snapshot
Bootloader U-Boot
Target mediatek
System-On-Chip MediaTek MT7621A
CPU MHz 880
Flash MB 128NAND
RAM MB 256
Ethernet 100M ports -
Ethernet Gbit ports 5
Switch MediaTek MT7530
Modem -
Comments - network ports
WLAN 2.4GHz b/g/n
WLAN 5.0GHz a/n/ac
WLAN Hardware MediaTek MT7603EN, MediaTek MT7615N
Detachable Antennas -
Comments - WLAN 2.4 - 2x2, 5 - 4x4
USB ports 1x 3.0
SATA ports -
Serial Yes
Comments - USB & SATA ports
LED count 5
Button count 2
Power supply 12 VDC, 1.5 A
Forum Topic URL
WikiDevi URL
OEM device homepage URL http://¿
Firmware OEM Stock URL http://¿
Firmware OpenWrt Install URL http://¿
Firmware OpenWrt Upgrade URL http://¿
Edit the underlying data View/Edit data

Insert photo of front of the casing

Insert photo of back of the casing

Backside label:
Insert photo of backside label

Note: This will void your warranty!

There are 2 crews behind the rubber feet. There are also clips around the edge of the case you will need to prize open, using, for example, a plastic card.

Rostelecom RT-SF-1 case opening

Main PCB:
Insert photo of PCB

port.serial general information about the serial port, serial port cable, etc.

How to connect to the Serial Port of the Etisalat S3:
Beeline SmartBox TURBO UART connection

You need to connect R53 and R54 pins (marked red on the photo). For example using the solder.

Serial connection parameters
for Etisalat S3
57600, 8N1, 3.3V

port.jtag general information about the JTAG port, JTAG cable, etc.

How to connect to the JTAG Port of this specific device:
Insert photo of PCB with markings for JTAG port

None so far.



OpenWrt community builds (unofficial)

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  • Last modified: 2023/01/17 08:04
  • by shahid