Abstract
Middleboxes are crucial for improving network security and performance, but only if the right traffic goes through the right middleboxes at the right time. Existing traffic-steering techniques rely on a central controller to install fine-grained forwarding rules in network elements - at the expense of a large number of rules, a central point of failure, challenges in ensuring all packets of a session traverse the same middleboxes, and difficulties with middleboxes that modify the 'five tuple.' We argue that a session-level protocol is a fundamentally better approach to traffic steering, while naturally supporting host mobility and multihoming in an integrated fashion. In addition, a session-level protocol can enable new capabilities like dynamic service chaining, where the sequence of middleboxes can change during the life of a session, e.g., to remove a load-balancer that is no longer needed, replace a middlebox undergoing maintenance, or add a packet scrubber when traffic looks suspicious. Our Dysco protocol steers the packets of a TCP session through a service chain, and can dynamically reconfigure the chain for an ongoing session. Dysco requires no changes to end-host and middlebox applications, host TCP stacks, or IP routing. Dysco's distributed reconfiguration protocol handles the removal of proxies that terminate TCP connections, middleboxes that change the size of a byte stream, and concurrent requests to reconfigure different parts of a chain. Through formal verification using Spin and experiments with our prototype, we show that Dysco is provably correct, highly scalable, and able to reconfigure service chains across a range of middleboxes.
Original language | English (US) |
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Article number | 9264708 |
Pages (from-to) | 423-437 |
Number of pages | 15 |
Journal | IEEE/ACM Transactions on Networking |
Volume | 29 |
Issue number | 1 |
DOIs | |
State | Published - Feb 2021 |
All Science Journal Classification (ASJC) codes
- Software
- Computer Science Applications
- Computer Networks and Communications
- Electrical and Electronic Engineering
Keywords
- NFV
- Session protocol
- middleboxes