here are a list of some besat and metabox equivalents. as for your besat 3500, pls check which software it has right now. if it is running on DS (dreamsoft) or MTG software, then chances are it is a clone of metabox (since besat is the authorised distributor of metabox for KSA).
same as metabox3.
BeSat 5400 Gold: DVB-S, embedded Multicas, 2x Common Interface
BeSat 2400 SuperGold: DVB-S, embedded Multicas, 2x Common Interface
BeSat EM 9001 CXCI: DVB-S, embedded Conax, 2x Common Interface
Same as metabox1
BeSat eM Bx: DVB-S, FTA
BeSat 3400: DVB-S, FTA
BeSat 3300: DVB-S, FTA
same as metabox2
BeSat 5300: DVB-S, embedded Conax
*courtesy of Satdiy