The SOT600E series small digital group telephone exchange adopts a modular design structure and a non blocking digital switching network. The product has more than 70 powerful hotel management and business office functions, which can provide various telephone management application solutions for IP networks, hotels, office buildings, campus networks, industrial and mining enterprises, government institutions and military units, public security, electricity, coal mines, petrochemicals, railways, banks and other private network systems. It can also be used as an end or access device for telecommunications and China Unicom (PCM relay E1 to FXS analog extension or IMS to FXS analog extension), making it an ideal device for user units to improve communication conditions, increase work efficiency, control telephone expenses, and implement office intelligence. Capacity: Add 16 to 88 line extensions and 1-4 digital relays E1 for both internal and external lines