On scalable service function chaining with O(1) flowtable entries

Yi Ren, Tzu-Ming Huang, Kate Ching-Ju Lin, Yu-Chee Tseng

Research output: Chapter in Book/Report/Conference proceedingConference contribution

8 Citations (Scopus)
57 Downloads (Pure)


The emergence of Network Function Virtualization (NFV) enables flexible and agile service function chaining in a Software Defined Network (SDN). While this virtualization technology efficiently offers customization capability, it however comes with a cost of consuming precious TCAM resources. Due to this, the number of service chains that an SDN can support is limited by the flowtable size of a switch. To break this limitation, this paper presents CRT-Chain, a service chain forwarding protocol that requires only constant flowtable entries, regardless of the number of service chain requests. The core of CRT-Chain is an encoding mechanism that leverages Chinese Remainder Theorem (CRT) to compress the forwarding information into small labels. A switch does not need to insert forwarding rules for every service chain request, but only needs to conduct very simple modular arithmetic to extract the forwarding rules directly from CRT-Chain's labels attached in the header. We further incorporate prime reuse and path segmentation in CRT-Chain to reduce the header size and, hence, save bandwidth consumption. Our evaluation results show that, when a chain consists of no more than 5 functions, CRT-Chain actually generates a header smaller than the legacy 32-bit header defined in IETF. By enabling prime reuse and segmentation, CRT-Chain further reduces the total signaling overhead to a level lower than the conventional scheme, showing that CRT-Chain not only enables scalable flowtable-free chaining but also improves network efficiency.
Original languageEnglish
Title of host publicationIEEE INFOCOM 2018 - IEEE Conference on Computer Communications
PublisherThe Institute of Electrical and Electronics Engineers (IEEE)
Number of pages9
Publication statusPublished - 11 Oct 2018
EventIEEE INFOCOM 2018 - IEEE Conference on Computer Communications - Honolulu, HI, USA
Duration: 16 Apr 201819 Apr 2018


ConferenceIEEE INFOCOM 2018 - IEEE Conference on Computer Communications

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