TP-Link TL-MR3420 is an beautiful 3G/4G Wireless N Router which allows sharing of high-speed 3G/4G CDMA/GSM data over WiFi and LAN, the router features an comprehensive list of supported USB data dongles and is plug-n-play compatible with majority of them. However, despite being shown supported the BSNL ZTE AC8700 EVDO modem refused to connect, even after using the latest official firmware from TP-Link's website it refused to connect while the modem get successfully identified. Finally, after getting the BETA firmware directly from TP-Link India's support desk it worked. Direct download link and process to flash this working beta firmware "mr3420v2_en_3_13_27_up_boot(121212)Beta.bin" is posted below.
I have been providing internet access to my Raspberry Pi via an TP-Link WiFi 3G Router, however we can directly connect a GSM/EVDO 3G dongle to any Linux computer and make it act like a WiFi access point using Linux utilities like WICD Network Manager. Configuring a EVDO modem to work on Linux can get a bit tricky, here is a simple to follow howto guide on setting things up.
While the auction of 3G spectrum is still to happen for private telecommunication players in India, state owned telecom operator BSNL is slowly rolling out their 3G services across cities and towns across the country. If you are from the lucky few cities and towns where BSNL 3G service is available here are all the information you will need to get started with 3G internet on your supported devices.
Basically, you will be needing a 3G supporting Cellphone or Data-card (eg. Micromax 3G Data-card) with an activated BSNL 3G SIM card with proper recharges to use the service, do keep in mind that you can migrate your existing 2G BSNL SIM-Card to 3G plans with a Re. 1/- recharge but this is not advised as it will wipe-out all your existing enrolled special-tariff schemes and validity promos - you can get a new 3G SIM for just Rs. 59/- and an 3G activation top-up of Rs. 120/- under a special promo till 31-12-09 which also provides you following benefits.
EVDO is the 
While the auction of 3G spectrum is still to happen for private telecommunication players in India, state owned telecom operator BSNL is slowly rolling out their 3G services across cities and towns across the country. If you are from the lucky few cities and towns where BSNL 3G service is available here are all the information you will need to get started with 3G internet on your supported devices.