BGP Flow-Spec Traffic Compress Action

BGP Flow Specification and its evolution to Version 2 (FSv2) specified in allow for the dissemination of traffic flow specification rules and traffic filtering actions. Traditional Flow-spec actions define widely-used filtering behaviors such as discard, rate limit, and traffic marking. Data transmitted across enterprise networks, data centers, and external connections varies widely in nature (e.g., database payloads, bulk text, multimedia, and signaling). Certain traffic aggregates present significant redundancy and high compression ratios, whereas other data streams have little to no compression potential or require dedicated processing hardware. While BGP Flow-spec enables network-wide policy distribution, static configurations lack the agility required for dynamic data-center interconnect (DCI) traffic engineering. Therefore, this document introduces a new BGP Flow-spec action that enables network operators to dynamically apply traffic compression based on granular traffic filters, saving core transport bandwidth and improving overall network utilization.

This document proposes a new BGP extended community called the "flow- spec traffic compress action". It operates as a Generic Transitive Extended Community type ("0x80"). The sub-type value [to be assigned by IANA] indicates that the global administrator and local administrator fields encode a flow-spec traffic compress action aligned with FSv2 action guidelines. In this extended community, the 2-byte global administrator field encodes compression algorithms referred to as Compression Parameter Index (CPI) [RFC3173]. The 4-byte local administrator field carries compression parameters (CPV). The new BGP extended community is encoded as follows:

Sub-Type: TBD. CPI (2 octets): The values 0-63 designate well-known compression algorithms. The values 64-255 are reserved for future use. The values 256-61439 are negotiated between the endpoints in the definition of an IPComp Association . CPV (4 octets): Parameters associated with the selected CPI. Depending on the CPI, the CPV can be divided into distinct segments (e.g., algorithm tuning flags, window sizes, or application IDs). Unused bits MUST be set to zero by the originating BGP speaker and ignored upon receipt.For instance, when utilizing the zstd compression algorithm, the CPV can be structured as: <trainAppId (1 octet), CRC (2 octets), appId (1 octet)>.

Generally, the ingress node receiving the Flow-spec Traffic Compress Extended Community acts as the compression controller or enforcement point, directing matching packets through hardware or software compression pipelines before forwarding them across bandwidth-constrained WAN/DCI links.

Because compression and decompression introduce processing overhead, transit nodes receiving this action MUST verify that they possess the hardware or software capabilities corresponding to the requested CPI. If a node lacks the requested compression capability, it MUST fall back to standard uncompressed forwarding or report a local policy exception, preventing packet dropping due to processing failures.

If multiple traffic compression extended communities exist in a BGP route attribute, the value of the first traffic compression extended community MUST take precedence. The validation of the TLVs and extended community structures introduced in this document MUST be performed to verify formatting correctness. In case of any malformed attributes detected, error handling MUST comply with and the error policies defined in .

IANA is requested to create a new entry/registry under the "Extended Community" registries:

Traffic compression introduces potential vector risks, such as CPU exhaustion (Denial-of-Service) attacks caused by malformed or highly inefficient payload structures designed to trigger worst-case compression cycles. Operators SHOULD implement rate-limiting or resource quotas on compression-enabled forwarding engines. Furthermore, standard BGP security mechanisms (such as RPKI and BGP session authentication) MUST be deployed to prevent unauthorized injection of compression action extended communities.

The authors would like to acknowledge the review and inputs from Haibo Wang, Gang Yan, Linda Dunbar, Zhenbin Li, Rainbow Wu, Jie Dong and Ziqing Cao.