Security Multimedia collaboration 911 calls on Internet Reliability and scalability Peer-to-peer systems Ubiquitous computing Service discovery Mobile and ad hoc Wireless telephony presence Programmable services Enterprise IP telephony
Limited description or query -- attribute-value or interface matching
A global service discovery architecture
Scalable (avoid central dependency)
Robust and self adjusting
Use modern description logic (OWL)
Global service discovery GloServ: Hierarchical P2P Global Service Discovery Architecture
Classify services using OWL
Use service classification to map ontology to a hierarchical P2P network (using CAN for p2p)
Bootstrap servers using information in ontology
Intelligent registration and querying
Knarig Arabshian 4) Send the query to the closest high-level server that is known Service Restaurant Travel Medical Communication Destination Flights Agencies Hotel Bed&Breakfast domain: hotel.destination.service 2) Map the word “ inn” to “hotel” 1) Query for “inn” is issued 3) Look up the domain of the equivalent server or closely related server in the primitive skeleton ontology 1 3 4 2 Hotel hostel inn rooming lodging motel
Global service discovery GloServ: Hierarchical P2P Global Service Discovery Architecture Knarig Arabshian (CampGround) 3 3 (Sightseeing) (Hotel) 20 hasActivity <1,2> <3,2> <1,3> <3,3> <2,1> <2,2> . . . <2,3> <10,2> <10,3> hasAccommodation (Budget) 2 1 (Sports) 2 (Adventure) CAN DHT distribution of properties CAN DHT CAN DHT CAN DHT CAN DHT
Optimal depth=2, select breadth such that prob. delivery =1
Wing Yuen (Andy) depth=4 breadth=2
7DS for mobile platforms Source: ARCChart – Developing for Mobile Environments Derek
Wireless VoIP Overview of the network and problems Sangho Shin Andrea Forte R1 AP2 AP1 Internet Access-point Router Subnet A Subnet B R2 Layer 2 handoff Layer 3 handoff Handoff delay (Layer 2 and Layer 3) Limited capacity Call admission control
Duplicate Address Detection (DAD) Before the DHCP server decides to assign an IP address, it has to be sure that such address is not already in use. In order to do this, the DHCP server sends ICMP Echo requests and waits for ICMP Echo replies.
The delay introduced by DAD is in the order of seconds!
Passive DAD (P-DAD) We introduce a new agent, namely Address Usage Collector (AUC), which collects information about the IP addresses in use in its subnet. The AUC will then inform the DHCP server about IP addresses already in use in a particular subnet.
In wireless networks , it takes long time to get ICMP echo response, or even the response can be lost when the channel is very congested.
Windows XP SP2 activates the firewall, and the firewall blocks incoming ICMP echo by default.
ISC DHCP software has a bug in the DAD timer, and the timer value is decided between 0 ~ 1 sec randomly.
Sangho Shin Andrea Forte
VoIP real world app. Training air traffic controllers at FAA
Existing communication system
Voice communications network
Analog, fixed point-to-point connections
Fast Ethernet data network
Depends on analog, hard-wired communication systems that use obsolete parts no longer available without custom manufacture
What the project is?
Simulate a FAA classroom
Classroom has student, pilot and an instructor workstation
Student plays the role of an ATC, who is trained by the pilot.
Student and pilot communicate to each other, via a notion of frequency (unicast) and facility (multicast)
What am I doing?
Get the project successfully deployed on-site
Development of robust audio tool on Windows platform
Venkata S. Malladi Anurag Chakravarti
Session peering for multimedia and VoIP interconnect
Motivation: expenses, overhead, flexibility of end-to-end IP-based services.
How it is done: switch fabric, rules and regulations that manage sending and receiving data among one another.
Challenges: Architecture, QoS, Security, Operations Support Services, Reliability, Protocol Interoperability, Call routing, ENUM, etc.
Charles Shen IP Phone IP Phone SIP based Network PSTN PSTN (telephone) SIP based Network Existing architecture Direct Peering
ENUM Marriage of Internet and telephone numbering
Bridges traditional telephony with Internet capabilities into a platform for new services and applications.
Charles Shen SIP Proxy SIP Proxy Enum Server  Caller dials callee’s normal phone number 212-939-7040  Caller’s proxy queries Enum for 0.4.0.7.18.104.22.168.1.2.1.e164.arpa and gets response sip:email@example.com  Caller’s proxy receives response sip:firstname.lastname@example.org and proceed to set up call with the callee Caller Callee
Session peering and ENUM Status quo and our work
WGs in standardization bodies such as IETF SPEERMINT, ENUM WG and SIPForum technical WG are working on requirements and architecture details for a Session Peering for Multimedia Interconnect architecture.
I am currently involved in ENUM server performance investigation and expected to contribute to other parts of the peering architecture as well.
VoIP security Trust path discovery for SPAM detection
Motivation : option for sender filtering against spam (SPIT/SPIM)
Determine whether to accept communication’s requests, e.g., emails, calls, instant messages from a “stranger”
Based on reputation of that stranger
Challenge : how to get the stranger’s reputation
Gathering trustworthy opinions on individuals and their domains from trust paths
Opinions : based on trust indicators which represent one’s trust on receiving messages
Trust paths : chains of trust relationships; among individuals, among domains and between an individual and a domain
Kumiko Ono Alice Dave A third party reputation system i.e., a server of social network 2. Query his reputation 1. Receive communication request Related Work 1. Receive communication request Alice Dave Trust paths i.e., buddy-list, call-log 2. Query his reputation Our Approach
Rules about how and what part of presence info can be accessed
More detailed information includes location, preferred communication mode, current mood and activity
Represents a user or a group of users or a program
Source of presence information
Requester of presence information about a presentity
Vishal Singh Bob’s Presentity Bob is busy right now. He is on 42 nd ,Broadway . U can reach him after 4.00 p.m . on his office line .
Presence Presentity and Watchers Bob’s status, location Available , Busy , Somewhat available , Invisible wife son colleague external world PUBLISH SUBSCRIBE NOTIFY Bob’s Presentity Bob’s Presence User Agents (PUA) PC-IM Client R u there ? Cell Phone BUZZ PUBLISH Bob’s Filters (Rules), PIDF Presence Server Vishal Singh Watchers Watchers Watchers
Presence Deployment: Cross-domain SIP NOTIFY SIP SUBSCRIBE Presence Database Broadband IP Network (VoIP, Internet) IM Vishal Singh Presence Server Presence Server Presence Server Watchers/Buddies for one presentity Presence Server Presence Server Watchers/Buddies for one presentity PSTN SCP Wireless Network SIP PUBLISH SIP PUBLISH SIP PUBLISH SIP Phone TV
Kundan Singh Program Call routing SIP SAP RSVP RTCP RTP Media G.711 MPEG RTSP Signaling Quality of service Media transport Internet Telephony Internet Radio/TV Messaging and Presence Interactive voice response Unified messaging Video conferencing Physical layer Link layer Network (IPv4, IPv6) Transport (TCP, UDP) Application layer Voice XML DTMF Mixing Speech/ text SDP Program Call routing SIP SAP RSVP RTCP RTP Media G.711 MPEG RTSP Signaling Quality of service Media transport Internet Telephony Internet Radio/TV Messaging and Presence Interactive voice response Unified messaging Video conferencing Physical layer Link layer Network (IPv4, IPv6) Transport (TCP, UDP) Application layer Physical layer Link layer Network (IPv4, IPv6) Transport (TCP, UDP) Application layer Voice XML DTMF Mixing Speech/ text SDP
VoIP infrastructure Reliability and scalability
Load sharing: scalability
Kundan Singh REGISTER INVITE P1 P2 P3 a-h i-q r-z Use DNS
Peer-to-peer Analysis of the Skype peer-to-peer VoIP application Salman Abdul Baset Process priority Memory usage 10 109 ms Normal Normal 13 MB, 13 MB 9 MB, 9 MB 22.214.171.124 G-Talk 16 184 ms Normal Normal 34 MB, 31 MB 25 MB, 22 MB 7.5 MSN 12 152 ms Normal Normal 43 MB, 42 MB 38 MB, 34 MB 126.96.36.1997 Yahoo 4 96 ms High Normal 21 MB, 27 MB 19 MB, 19 MB 188.8.131.52 Skype Latency Standard Deviation Mouth-to-ear latency during call before call during call (caller, callee) before call (caller, callee) Application version Application
Peer-to-peer Churn in small scale p2p networks
Small scale: nodes count 5 to 1000
Churn: node arrival/departure rate
Office: high churn at 9:00am and 5:00pm
Is distributed hash table (DHT) better than flooding?