Media-Aware Network Elements on Legacy Devices

Media‐Aware Network Elements  on Legacy Devices   m16695  Ingo Koﬂer, Robert Kuschnig, and Hermann Hellwagner  Chris:an Timmerer  Klagenfurt University (UNIKLU)  Faculty of Technical Sciences (TEWI)  Department of Informa:on Technology (ITEC)  Mul:media Communica:on (MMC)  h;p://research.@mmerer.com  h;p://blog.@mmerer.com  mailto:chris@an.@mmerer@itec.uni‐klu.ac.at  Acknowledgement: Part of this work is supported by the European Commission in the  context of the and ENTHRONE (contract no. 038463) project. Further informa@on is  available at h;p://www.ist‐enthrone.org.  

Outline  •  Mo@va@on and Introduc@on  •  List of Technologies  •  Architecture and Performance Evalua@ons  •  Demo Video  •  Conclusions / References  2009/07/01  Chris@an Timmerer, Klagenfurt University, Austria  2 

Mo@va@on and Introduc@on  •  Adapta@on of an SVC bitstream  –  Achieved by removing certain NALUs ➙ filtering of NALUs  –  Steered by a (TID, DID, QID) tuple ➙ filter criteria  –  Computa@onally cheap (compared to transcoding etc.)  •  Idea  –  Perform real‐@me in‐network adapta@on of the SVC bitstream  on an ordinary, low‐cost WiFi router  –  Media‐aware Network Element (MANE)  •  Applica@ons of in‐network adapta@on  –  Cross‐layer adapta@on on the access point  –  Adapta@on for different end‐devices  2009/07/01  Chris@an Timmerer, Klagenfurt University, Austria  3 

Media‐aware Network Element  On‐the‐ﬂy adapta@on of scalable coded video content in a media‐ aware network element (MANE).  Source: h;p://ip.hhi.de/imagecom_G1/savce/  2009/07/01  Chris@an Timmerer, Klagenfurt University, Austria  4 

List of Technologies  •  Scalable Video Coding (SVC)  •  Real‐@me Streaming Protocol (RTSP)  –  Establishing and controlling the streaming session  –  VCR‐like control of the streaming (Start, Stop, Pause)  •  Real‐@me Transport Protocol (RTP)  –  Encapsulates the video and/or audio content  –  Mostly used on top of the unreliable UDP protocol  –  Oﬀers sequence number, @mestamps for syncing the  playback  –  Generic header with content‐speciﬁc payload format  (AVC, SVC, …)  2009/07/01  Chris@an Timmerer, Klagenfurt University, Austria  5 

Proxy Approach server  router with proxy  router  client  RTSP  RTP/RTCP  RTSP  RTP/RTCP  RTSP  RTP/RTCP  TCP  UDP  TCP  UDP  TCP  UDP  IP  IP  IP  MAC/PHY  MAC/PHY  MAC/PHY  •  Proxy on network device between client & server –  Intercepts the RTSP / RTP communication –  Proxy is transparent for the client –  Acts as client for initial server and as server for the client •  Implications –  Proxy has to modify parts of the request (e.g. port numbers) –  Proxy can then adapt the SVC video stream carried over RTP 2009/07/01  Chris@an Timmerer, Klagenfurt University, Austria  6 

Proxy Approach (cont’d)  Beneﬁts  Drawbacks  •  Session‐ and stream‐/ •  Proxy is running as user‐ media‐awareness   space process   •  Enables stateful inspec@on  •  RTP packets have to be  and processing of packets  passed (copied) from the  •  Allows adapta@on on a per‐ kernel‐space to the user‐ session basis  space and vice versa  •  Consistent RTCP receiver  •  Decreases theore@cal  and sender reports  throughput compared to  kernel‐internal solu@on (e.g.  ﬁltering on IP level)  2009/07/01  Chris@an Timmerer, Klagenfurt University, Austria  7 

Architecture  Handles incoming RTSP requests (554  redirect to proxy using iptables)  SDP stored in LRU‐based cache un@l  session established  Maintains state: seq#, @mestamps,  SVC params, monitoring, etc.  Forwards non‐SVC packets  Adapts SVC packets  Acts as server for client  Acts as client for server  Retrieve monitoring informa@on  Modify adapta@on/SVC parameters  2009/07/01  Chris@an Timmerer, Klagenfurt University, Austria  8 

Performance Evalua@ons  •  Hardware: Linksys WRT 54 GL  –  Broadcom System‐on‐Chip BCM5352EL  –  MIPS32 200 MHz CPU  –  16 MB RAM  –  4 MB Flash Memory  –  IEEE 802.11b/g WLAN  –  Fast Ethernet switch with 5 ports  –  price ~ 45 Euros  (May 2008)  •  Sonware: OpenWrt  –  Linux‐based ﬁrmware for Broadcom‐based WiFi routers  –  gcc-based SDK for OpenWrt available –  Proxy implementa@on in ANSI C  2009/07/01  Chris@an Timmerer, Klagenfurt University, Austria  9 

Performance Evalua@ons (cont’d)  •  Evalua@on of the implementa@on on the target plaporm  –  Server – proxy – client deployment  –  Inves@ga@on of worst‐case scenario (no adapta@on)  •  Performance metrics  –  CPU usage for diﬀerent number of streams  –  Delay introduced by the proxy on a complete access unit (frame)  •  Three diﬀerent SVC streams for evalua@on  –  Foreman, CIF, 30 Hz, 715 kbps  –  City, 4CIF, 30 Hz, 1247 kbps  –  Harbour, 4CIF, 30 Hz, 2056 kbps  2009/07/01  Chris@an Timmerer, Klagenfurt University, Austria  10 

Performance Evalua@ons (cont’d)  CPU Usage  2009/07/01  Chris@an Timmerer, Klagenfurt University, Austria  11 

Performance Evalua@ons (cont’d)  CDF of delay for sequence city (1245 kbps)  2009/07/01  Chris@an Timmerer, Klagenfurt University, Austria  12 

Demo Video  2009/07/01  Chris@an Timmerer, Klagenfurt University, Austria  13 

Conclusions  •  Proxy approach for in‐network adapta@on on a per‐packet  basis  –  Aware of sessions and individual streams (media‐aware)  –  Stateful, not a simple packet dropper  •  Applica@ons  –  Adapta@on according to device capabili@es  –  Cross‐layer adapta@on  –  NAT traversal  •  Performance suﬃcient for typical home deployments  –  4 parallel streams with 30 percent CPU load and < 100 ms delay   ➙SVC adapta@on can be done on exis@ng oﬀ‐the‐shelf  network devices  2009/07/01  Chris@an Timmerer, Klagenfurt University, Austria  14 

References  •  I. Kofler, J. Seidl, C. Timmerer, H. Hellwagner, I. Djama and T. Ahmed,  “Using MPEG‐21 for cross‐layer mul@media content adapta@on”, Journal  on Signal, Image and Video Processing, Springer, vol. 2, no. 4, Dec. 2008.  •  R. Kuschnig, I. Kofler, M. Ransburg, H. Hellwagner, “Design op@ons and  comparison of in‐network H.264/SVC adapta@on”, Journal of Visual  Communica@on and Image Representa@on, Sept. 2008.  •  I. Kofler, M. Prangl, R. Kuschnig, and H. Hellwagner, “An H.264/SVC‐based  adapta@on proxy on a WiFi router”, Proceedings of the 18th Interna@onal  Workshop on Network and Opera@ng Systems Support for Digital Audio  and Video (NOSSDAV 2008), Braunschweig, Germany, May 2008.  •  I. Kofler, C. Timmerer, H. Hellwagner, and T. Ahmed: “Towards MPEG‐21‐ based Cross‐layer Mul@media Content Adapta@on”, Proc. 2nd  Interna@onal Workshop on Seman@c Media Adapta@on and  Personaliza@on (SMAP 2007), London, UK, Dec. 2007.  2009/07/01  Chris@an Timmerer, Klagenfurt University, Austria  15 

Thank you for your a;en@on  ... ques@ons, comments, etc. are welcome …   Ass.‐Prof. Dipl.‐Ing. Dr. Chris@an Timmerer  Klagenfurt University, Department of Informa@on Technology (ITEC)  Universitätsstrasse 65‐67, A‐9020 Klagenfurt, AUSTRIA  chris@an.@mmerer@itec.uni‐klu.ac.at  h;p://research.@mmerer.com/  Tel: +43/463/2700 3621 Fax: +43/463/2700 3699  © Copyright: Chris.an Timmerer  2009/07/01  Chris@an Timmerer, Klagenfurt University, Austria  16 

Media-Aware Network Elements on Legacy Devices

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Media-Aware Network Elements on Legacy Devices — Presentation Transcript