q_sali, you can use almost any time of external maps from any map provider including Google, but in that way map tiles(images) will be downloaded to client's browser directly from external map server.
You optionally can import into Wialon some kinds of map data (see link above) and such a way Wialon will be able to detect locations, lock messages to roads, search addresses, etc and most important all map tiles will be downloaded into client's browser directly from WIalon, e.g. if you put Wialon into LAN, then you will have it very fast.
At the
dark side of telematics...