Skype for Business (formerly Lync) is Microsoft's enterprise communications tool featuring chat, voice/video meetings, presence, and integration with Office and Exchange. It is being phased out in favor of Teams.

Skype for Business was previously available via on‑prem or cloud deployments; in China it functioned through 21Vianet‑operated cloud or enterprise servers. Its replacement, Teams (21Vianet-operated), offers better compliance across government and regulated industries.

The information regarding service availability in China is provided for general reference purposes only. Due to the dynamic nature of network conditions and regulatory environments, the actual accessibility of these services may vary over time and by location. Users are advised to verify the current status independently.