Cisco Systems

gmccollu@cisco.com

Network Time Protocols This document proposes a modern, secure, and extensible time synchronization protocol designed to operate over the QUIC transport protocol. Known as TSQ (Time Synchronization over QUIC), this protocol aims to address the limitations of traditional NTP by leveraging QUIC's encryption, widespread UDP/443 acceptance, and multiplexed stream capabilities. TSQ is designed for contemporary deployment environments, including enterprise networks, cloud-native systems, containers, and mobile devices, where traditional UDP-based NTP struggles with security, scalability, or operational reliability.

Time synchronization is foundational to modern computing. It underpins authentication systems, log correlation, distributed transactions, and more. NTP, the current standard, was designed in a different era and brings challenges related to security, deployment compatibility, and extensibility. TSQ is proposed as a new protocol built directly on top of QUIC, leveraging its modern transport features to provide secure, authenticated, and operationally-friendly time synchronization.

TSQ is intended to: Provide secure and authenticated time synchronization Support modern deployment scenarios Operate in environments where UDP/123 is blocked Be extensible and future-proof Scale for enterprise and cloud TSQ is not intended to: Replace NTP in ultra-precise or constrained devices Replace public NTP infrastructure without optimization

TSQ uses QUIC as its transport, establishing secure, short-lived connections. A typical exchange: Client opens a QUIC connection to the TSQ server (UDP/443). Client sends a TSQ Request with nonce and timestamp request. Server replies with timestamps, echoed nonce, and metadata. Client calculates RTT and adjusts clock accordingly.

TSQ relies on QUIC’s handshake for mutual authentication, confidentiality, and replay protection. Optional Ed25519 or HMAC signatures can be added if auditability is required. By default, QUIC session integrity suffices.

Short-lived connections, session resumption, and optional stateless design support scalability. TSQ is suitable for enterprise and cloud deployments.

TSQ Request Type: 0x01 Nonce (16 bytes) Optional extensions TSQ Response Type: 0x02 Echoed Nonce Server Time Receive Timestamp Send Timestamp Optional metadata and signature

Cloud/container infrastructure Mobile clients Firewalled enterprise networks High-precision timing visibility

Comparison to Existing Protocols The following table highlights key differences between traditional NTP, NTS, and the proposed TSQ protocol: Feature NTP NTS TSQ TransportUDPUDP+TLSQUIC (UDP/443) EncryptionNoYesAlways ExtensibilityLowMediumHigh Mobile SupportNoNoYes Precision ModeNoNoYes

Solicit feedback on sync behavior and design Improve trust and crypto model Implement prototype in QUIC Submit official Internet-Draft if interest grows

Thanks to contributors from the QUIC and NTP working groups for input on timing accuracy and protocol design.

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