Peer-to-peer systems for autonomic VoIP and web hotspot handling

0 comments

file time: 2008-03-22

file siez:263.5KB

filetype:ppt

Click Here To Download...

>   

Peer-to-peer systems for autonomic VoIP and web hotspot handling 

Kundan Singh, Weibin Zhao and Henning Schulzrinne

Internet Real Time Laboratory

Computer Science Dept., Columbia University, New York

identifier lookup NAT traversal: media traversal OpenDHT (and similar) as emerging common infrastructure? Non-DHT systems with smaller scope 00web hotspot rescue Network management (see our IRTF slides)  

Dagstuhl Seminar on Autonomic Systems (Jan. 2006)  

3  

Aside: autonomic characteristics 

Autonomic characteristics (self-*) determine success for consumer applications: web-based email programs consumer IM Skype Apple Rendezvous, DHCP IETF and IEEE slowly starting to take note: old techniques (ICMP) no longer working netconf: XML-based network configuration instead of CLI and (rarely) SNMP XCAP: generic XML configuration manipulation SIP auto-configuration work IEEE 802.1 network discovery (LLDP, 00 concerns about network complexity  

Dagstuhl Seminar on Autonomic Systems (Jan. 2006)  

4  

What is SIP? Why P2P-SIP? 

Bob00 host 

Alice00 host

128.59.19.194 

(1) REGISTER

      alice@columbia.edu =>128.59.19.194 

(2) INVITE  alice@columbia.edu 

(3) Contact: 128.59.19.194 

columbia.edu 

Problem in client-server: maintenance, configuration, controlled infrastructure 

Peer-to-peer network 

Alice

128.59.19.194 

(1) REGISTER 

(2) INVITE alice 

(3) 128.59.19.194 

No central server, but more lookup latency

 

Dagstuhl Seminar on Autonomic Systems (Jan. 2006)  

5  

How to combine SIP + P2P? 

SIP-using-P2P Replace SIP location service by a P2P protocol   P2P-over-SIP Additionally, implement P2P using SIP messaging   

P2P network 

Alice

128.59.19.194 

INSERT 

INVITE sip:alice@128.59.19.194 

P2P-SIP

overlay 

Alice

128.59.19.194 

REGISTER 

INVITE alice 

FIND 

SIP 

SIP 

P2P 

Lookup 

SIP 

P2P 

P2P 

Maintenance 

P2P-over-SIP 

P2P SIP proxies 

SIP-using-P2P

 

Dagstuhl Seminar on Autonomic Systems (Jan. 2006)  

6  

Deployment scenarios 

P 

P 

P 

P 

P 

P2P proxies 

P 

P 

P 

P 

P 

P2P database 

P 

P 

P 

P 

P 

P2P clients 

Plug and play;

May use adaptors;

Untrusted peers 

Zero-conf server farm;

Trusted servers and

user identities 

Global, e.g., OpenDHT;

Clients or proxies can use;

Trusted deployed peers (?) 

Interoperate among these!

 

Dagstuhl Seminar on Autonomic Systems (Jan. 2006)  

7  

Hybrid architecture 

Cross register, or Locate during call setup DNS, or P2P-SIP hierarchy  

Dagstuhl Seminar on Autonomic Systems (Jan. 2006)  

8  

What else can be P2P? 

Rendezvous/signaling (SIP) Configuration storage Media storage (e.g., voice mail) Identity assertion (?) PSTN gateway (?) NAT/media relay (find best one)  

Trust models are different for different components!

 

Dagstuhl Seminar on Autonomic Systems (Jan. 2006)  

9  

What is our P2P-SIP? 

Unlike server-based SIP architecture Unlike proprietary Skype architecture Robust and efficient lookup using DHT Interoperability DHT algorithm uses SIP communication Hybrid architecture Lookup in SIP+P2P Unlike file-sharing applications Data storage, caching, delay, reliability Disadvantages Lookup delay and security  

Dagstuhl Seminar on Autonomic Systems (Jan. 2006)  

10  

Implementation: SIPpeer 

Platform: Unix (Linux), C++ Modes: Chord: using SIP for P2P maintenance OpenDHT: using external P2P data storage Scenarios: P2P client, P2P proxies Adaptor for existing phones Cisco, X-lite, Windows Messenger, SIPc Server farm  

Dagstuhl Seminar on Autonomic Systems (Jan. 2006)  

11  

Implementation: SIPpeer 

User interface (buddy list, etc.) 

SIP 

ICE 

RTP/RTCP 

Codecs 

Audio devices 

DHT (Chord) 

On startup 

Discover 

User location 

Multicast REGISTER 

Peer found/

Detect NAT 

REGISTER 

REGISTER,

INVITE,

MESSAGE 

Signup,

Find buddies 

Join 

Find 

Leave 

On reset 

Signout,

transfer 

IM,

call 

SIP-over-P2P 

P2P-using-SIP

 

Dagstuhl Seminar on Autonomic Systems (Jan. 2006)  

12  

SIP p2p summary and open issues 

Advantages Out-of-box experience Robust catastrophic failure-unlikely Inherently scalable more with more nodes Status IETF involvement Columbia SIPpeer   Security issues Trust, reputation malicious node, sybil attack SPAM, DDoS Privacy, anonymity (?) Other issues Lookup latency,proximity P2P-SIP vs SIP-using-P2P Why should I run as super-node?  

   download Peer-to-peer systems for autonomic VoIP and web hotspot handling