TCP/ICN: Carrying TCP over Content Centric and Named Data Networks

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Marsha McDowell
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1 TCP/ICN: Crrying TCP over Content Centric nd Nmed Dt Networks Ily Moiseenko Cisco Systems Dve Orn Cisco Systems

2 Outline I. Introduction II. Design Bsic fetching proxy Relible prefetching proxy Unrelible prefetching proxy III. Evlution IV. Conclusions 2

3 I. Introduction 3

4 Why Bother? You could just run Dul-Stck in Ships-in-the-night mode. But mjor ttrction of ICN is simplifiction nd performnce in environments not friendly to IP: Mobile edge eliminte tunnels, respond more quickly to mobility events, temporl cching t the edge for better error control IoT Much smller code footprint, better integrtion with rdio protocols, lower bckground chtter thn IP 4

5 High-level gols 1. Unltered TCP/IP stck nd pplictions 2. Preserve TCP end-to-end semntics Split-TCP functionlity cn be dded fterwrds 3. Pull dt between proxies (i.e. don t require dt push in Interests) 4. Comptibility with both CCN nd NDN 5. Minimize overhed 5

6 Non-gols 1. Support of UDP or other trnsport protocols 2. Heterogeneous ddressing nd routing Ech proxy owns routble nme prefix Do not propose IP ddr <-> nme prefix mpping 3. Pth MTU-discovery nd frgmenttion Assume stndrd 1500-byte TCP MSS nd up to 9000 bytes ICN Dt messges 6

7 II. Design 7

8 Min chllenges How to reconcile the TCP/IP push model with the ICN pull model? How to minimize infltion of messge count nd messge sizes? How much does the trnsltion function need to understnd the TCP stte mchine? How to mrry the ICN nd TCP congestion nd flow control models? 8

9 Design lterntives for TPC/ICN Proxies We designed nd evluted three pproches: Simple one-to-one mpping of TCP messges to ICN exchnges Trck the TCP stte mchine in the proxies to provide relibility over the ICN segment of the pth Mp TCP Dt to ICN Dt using n unrelible inter-proxy chnnel Connection stte mchine sme for ll three differ only in the dt phse 9

10 Shred prts /verizon FIN flg Interest: /<routble prefix>/<tcp/ip heders>/<nonce> /verizon SYN flg Interest: /<routble prefix>/<tcp/ip heders>/<nonce> /tt SYN, ACK flgs Interest: /<routble prefix>/<tcp/ip heders>/<nonce> /verizon ACK flg Interest: /<routble prefix>/<tcp/ip heders>/<nonce> /tt ACK flg Interest: /<routble prefix>/<tcp/ip heders>/<nonce> /tt FIN flg Interest: /<routble prefix>/<tcp/ip heders>/<nonce> /verizon ACK flg Interest: /<routble prefix>/<tcp/ip heders>/<nonce> TCP connection setup TCP connection terdown 10

11 Bsic fetching TCP$dt$$ segment$ 1" 2" Dt"cche" 3" 4" 5" Interest with TCP/IP heders Interest pulling dt Dt crrying TCP pylod 6" TCP$dt$$ segment$ TCP$$ ACK$ Interest with TCP/IP heders TCP$$ ACK$ TCP sender Forwrd proxy Reverse proxy TCP receiver Unidirectionl TCP flow Dt encpsultes TCP segment crrying pylod /[forwrd-proxy-prefix]/[tcp-4-tuple]/[tcp-sequence-number]/[wrpround-number] Interest encpsultes n empty TCP segment /[reverse-proxy-prefix]/[tcp-ip-heders]/[nonce] Slow: 2x RTT, 2x pckets 11

12 Relible prefetching Dt sequencing is independent from TCP sequencing Impossible to predict TCP sequence number progression TCP 4 tuple 129 Interest: /<routble prefix>/<connection id>/<sequence#> TCP 4 tuple 130 Interest: /<routble prefix>/<connection id>/<sequence#> TCP/IP: SEQ # ACK # TCP 4 tuple 129 Dt: /<routble prefix>/<connection id>/<sequence#> TCP/IP: SEQ # ACK # TCP 4 tuple 130 Dt: /<routble prefix>/<connection id>/<sequence#> TCP/IP: SEQ # ACK # SEQ # ACK # Interest: /<routble prefix>/<tcp/ip heders>/<nonce> Forwrd proxy Unidirectionl TCP flow 12

13 Relible prefetching TCP$dt$$ segment$ 1" cwnd" dver:ser" Interest" queue" Dt"queue"+"cche" 2" 3" 4" Interest per ech RTT Interest pipelining w.r.t cwnd Dt crrying TCP segment Relible" consumer" 5" TCP$dt$$ segment$ TCP$$ ACK$ Interest with TCP/IP heders 6" TCP$$ ACK$ TCP sender Forwrd proxy Reverse proxy TCP receiver Reverse proxy trnsmits n Interest prior to TCP segment rrivl t the forwrd proxy Enforces relibility Unidirectionl TCP flow Forwrd proxy dvertises pprox. TCP cwnd size Fster, but unstble. A lot of stte in the proxy. Other issues. 13

14 Unrelible prefetching Time-delyed nming Dt nmes mtch TCP sequence numbers delivered one RTT go TCP/IP: TCP/IP: TCP/IP: SEQ # ACK # SEQ # ACK # SEQ # ACK # SEQ # ACK # Interest: /<routble prefix>/<tcp/ip heders>/<nonce> SEQ # ACK # Dt: /<routble prefix>/<tcp/ip heders>/<nonce> SEQ # ACK # Interest: /<routble prefix>/<tcp/ip heders>/<nonce> Forwrd proxy Unidirectionl TCP flow 14

15 Unrelible prefetching TCP$$ ACK$ 3" Interest" queue" 2" Interest with TCP/IP heders 1" TCP$$ ACK$ TCP$dt$$ segment$ 4" Dt crrying multiple 5" TCP" TCP dt segments 6" queue" TCP$dt$$ segment$ TCP sender Forwrd proxy Reverse proxy TCP receiver Unidirectionl TCP flow Interests encpsulting ACKs prefetch new TCP segments Not enough ACKs due to delyed ACK TCP mechnism Pckge multiple TCP segments in single Dt messge No dditionl relibility in ICN protocol Fst. Comprble to TCP/IP (cubic). Sclble. 15

16 Unrelible prefetching A problem of full-duplex TCP connection: TCP piggybcks ACKs in the dt segments --> no Interests re sent by the proxies A proxy detects full-duplex by nlyzing ACK # Genertes Interests on its own Fixed probbility (e.g. 50% = every 2 nd segment) Function of ACK # progression 16

17 III. Evlution 17

18 Evlution TCP cubic over ICN vs. TCP cubic over IP TCP client IP forwrder IP forwrder IP forwrder TCP server TCP client NDNsim ICN forwrder TCP/ICN proxy TCP firewll Proof of concept *nix implementtion Unrelible prefetching ICN forwrder ICN forwrder TCP/ICN proxy TCP firewll TCP server 18

19 Flow completion time 0 Unrelible prefetching is 10% slower thn TCP/IP TCP sequence number 4e+07 2e+07 Unrelible prefetching Bsic fetching TCP cubic Relible prefetching Bsic fetching Relible prefetching TCP cubic 0e+00 Unrelible prefetching Time (ms) 19

20 TCP retrnsmissions Bsic fetching Bsic fetching Totl number of TCP retrnsmissions (pckets) Relible prefetching TCP cubic Unrelible prefetching TCP cubic Relible prefetching Unrelible prefetching Time (ms) 20

21 TCP congestion window size Cwnd (bytes) TCP cubic Relible prefetching Unrelible prefetching Bsic fetching Bsic fetching TCP cubic 0 Relible prefetching Time (ms) Unrelible prefetching 21

22 TCP retrnsmission timeout Bsic fetching Relible prefetching TCP cubic Unrelible prefetching RTO (ms) 1000 Relible prefetching 500 Bsic fetching Unrelible prefetching TCP cubic Time (ms) 22

23 Flow firness nd completion time Unrelible prefetching tcpperf tool + proxy PoC 10 competing unidirectionl flows Within 5% difference with TCP/IP TCP flow completion time (sec) TCP/ICN TCP/IP Fir TCP flow size (Mb) 23

24 Beyond synthetic tests Web browser ICN forwrder TCP/ICN proxy TCP firewll ICN forwrder ICN forwrder TCP/ICN proxy TCP firewll Web server TLS requires dditionl ccommodtions Inject extr Interests t TCP connection setup phse to fetch TLS server hello messges 24

25 Conclusions We cn run mny Internet pplictions without IP TCP is highly optimized for IP But it works surprisingly well over ICN! 25

26 Q/A 26

Readings : Computer Networking. Outline. The Next Internet: More of the Same? Required: Relevant earlier meeting:

Readings : Computer Networking. Outline. The Next Internet: More of the Same? Required: Relevant earlier meeting: Redings 15-744: Computer Networking L-14 Future Internet Architecture Required: Servl pper Extr reding on Mobility First Relevnt erlier meeting: CCN -> Nmed Dt Network 2 Outline The Next Internet: More