Subject: [ppsp] Incentive of PPSP - view from CDN/Cache providers

From: Ning Zong <[email-masked]>
Date: Fri, 07 Aug 2009 11:57:19 +0800

Hi, all,

Just want to clarify the incentive of PPSP from the view of CDN and cache
providers.

CDN/cache providers host/cache content from different SPs to improve the
service quality of SPs, as well as reduce transit traffic in ISP network.
Especially, when hosting/caching P2P streaming content from multiple P2P
streaming applications, CDN/cache need to understand various P2P streaming
protocols, which introduce complexity and high cost to CDN/cache providers.
So, from the perspective of CDN/cache providers, a standard P2P streaming
protocol is beneficial.

The following figure depicts a scenario where a CDN/cache provider supports
multiple P2P streaming applications. This shows that a unified protocol
between tracker and peer, as well as peer and peer is helpful to CDN/cache
provider. Note that P-T is unified peer-tracker protocol and P-P means
unified peer-peer protocol. P_1, P_2 denote current (private) protocol used
in individual P2P streaming applications App_1 and App_2. Comments are
welcome!

+--------------------------+
+---------------------------+

|   App_1.Tracker  |                                    |   App_2.Tracker  |

+--------------------------+
+---------------------------+

   *        #                                        #              *

   *           #  P-T (content report, etc)         # P-T               *

   *               #                        #                       *

   *             +===========================+                  *

P_1           |  CDN/cache device (Act as Peer)  |                P_2

   *             +===========================+                  *

   *                 #       #                                      *

   *             #  P-P          #  P-P (Chunk info exchange, etc)    *

   *          #                       #                             *

----------------------
----------------------------------------------

| App_1.Peer   |                         |         App_2.Peer           |

----------------------
----------------------------------------------

BR,

Ning Zong