Answer
Sep 18, 2026 - 10:05 AM
The VoIP protocol supported by your HP Poly Adapter determines its interoperability with different phone systems and service providers. SIP (Session Initiation Protocol) is widely regarded as the best and most versatile protocol, offering extensive compatibility and future-proofing for VoIP communications. Both the Poly ATA 400 1FXS and Poly ATA 402 2FXS support SIP protocol, which ensures they can be used with most modern ITSPs and VoIP systems. The availability of SIP-based adapters means users can benefit from broad compatibility and ease of integration with existing telephony infrastructure.
