Relocating the office and staying connected

Posted by Mattias Sandström on May 6, 2009

DevBlog Teaser

To get some change, Tangix has relocated the office to the Stockholm archipelago - the island of Ljusterö. A rented house is the new location for the next month with a beautiful nature surrounding the house (office and the view from the window overlooking the sauna by the water).

Staying connected was a critical problem to solve before we decided to relocate the office. The wireless broadband (“3G”) has been pretty well expanded in Sweden and many areas even have HSDPA (“Turbo-3G”) connectivity. Checking our operator (Swedish Telia) and the coverage areas for HSDPA (purple areas and the circles are installed base-stations) we saw that we sure picked a suitable spot for the offices - HSDPA is available.

Before signing the contract we went out visiting the location and using the Apple iPhone 3G and the iPhone application “Bredbandskollen” (Broadband Throughput Validator) to check the cellular coverage. Measurements showed that the iPhone was able to get a decent 2.8MBps uplink

Searching the Internet we came across the Ericsson W25 WWAN-router that seemed to be the perfect kind of equipment to connect the office to the Internet.

The W25 is a complete unit containing the WWAN interface (GSM/EDGE/UMTS and HSDPA), a WiFi (802.11 b/g) AP, 4 10/100 MBps Ethernet interfaces, and two analogue phone interface. Shopping around for the unit, we found it for just below $100 (799 SEK) including VAT and shipping. The unit is not locked to a specific operator which is a nice feature.

Setup was a breeze but some initial problems connecting to the UMTS network needed a series of firmware updates to solve. The unit shipped with a firmware that was more than two years old and obviously had some problems. I used a twin SIM-card to my normal cell phone subscription and inserted that into the unit. As the twin-SIM has a separate phone number, the analogue interfaces is used for a normal DECT phone and the main office numbers are diverted.

Another cool feature of the W25 is the network sharing functions. The unit can work as a server for printers and storage, implemented by the Samba server. Decent speeds for accessing the resources were measured. Do not expect too complex user permission settings, but for a quick way to transfer files it is adequate.

Administration of the W25 is done through a web-interface giving you the knobs and buttons you expect for a router in this price-range. Nothing too fancy related to firewall functions or NAT, but the basics are there. The statistics section gives a very good overview of the operation with WAN information and bandwidth usage for the current month and the previous:

The engineering (especially radio) heritage of Ericsson’s engineers are obvious in some areas, for example the cellular network configuration and WiFi setup that has probably more details than the normal user would need:

Network speed is found to be quite stable but the added delay in the cellular network makes some operations a bit more painful over cellular Internet connections. Accessing web-pages and downloading information from the Internet does not cause any problems, but using SSH to connect to remote servers adds a bit of latency and also the latency is not constant - ping times are varying between 250-550 ms compared to 175 ms in the “wired” office.

The W25 can be optionally be equipped with a battery that is charges when connected to mains and will provide a mobile WiFi-bubble for easy access to the Internet.

One compatibility problem have been found with my Dell D810 running Vista and the Dell WiFi card. Sometimes the laptop is not able to connect to the W25 and get an IP-address using DHCP. Connecting to the WiFi network works fine, but not IP-address is obtained. The same laptop running Windows XP connected just fine. The solution has been to decrease the security of the WiFi to WEP encryption but still a reboot is required sometimes to get the laptop to connect. The Mac Mini, the iPhone 3G or the iPod Touch have not any problems connecting.

Update: After upgrading the laptop to Windows 7 RC (build 7100), the connectivity problems were solved.

So far the office relocation is transparent, let’s hope it will continue to be a trouble-free month.

-- Mattias