VoIP and Desktop Video Teleconferencing

Voice and Desktop Video Teleconferencing over IP: 

Voice and Desktop Video Teleconferencing over IP Willis Kim 9 July 2005

Application Voice Quality: 

Application Voice Quality Only Level Possible in a PBX

IP Telephony (and Video) Enablers: 

Digital Signal Processor Advances Bigger, Cheaper Bandwidth IP Precedence, 802.1p, IntServ/RSVP, DiffServ Voice Data Voice IP Telephony (and Video) Enablers Data Exceeds Voice Over Voice Net Network Consolidation Usage Costs Trunk Charges QoS Advances Data H.323/MGCP/SGCP/SIP FRF.11/12 AAL1/2/5 Open Telephony Standards

Reason for Convergence on IP: 

Reason for Convergence on IP Convergence Delivers Reduced maintenance costs via common infrastructure Increased productivity andamp; Decreased Time-to-Deploy Better leverage of capital across multiple organizations Greater administration and operation efficiencies

Multiservice Networks: 

Single Infrastructure Packet-Based Multiservice Network Data Voice Video Internet Multiservice Networks Integration of data, voice, and video services into a single packet-based infrastructure using IP Both in enterprise and public service provider networks infrastructure

Open Standards: 

Open Standards H.323 - An International Telecommunications Union (ITU) interoperability protocol enabling cross-communication of multimedia products and applications over packet-based networks. Under H.323, multimedia products offered by one vendor can work with those of another, regardless of hardware compatibility. For example, a PC can share audio and video streams over either an intranet or the Internet. Applications are thus network-, platform-, and application-independent. Extension of ITU-T standard H.320 that enables videoconferencing over LANs and other packet-switched networks, as well as video over the Internet. SIP - Session Initiation Protocol (SIP) is a peer-to-peer, multimedia signaling protocol developed in the IETF. SIP is ASCII-based, resembling HTTP, and reuses existing IP protocols (DNS, SDP, etc.) to provide media setup and teardown. Since its first publication in 1999, SIP has generated a high level of interest in the VoIP industry, and many people believe that SIP will become the de facto standard protocol for future voice networks.

Non-Open Standards: 

Non-Open Standards SCCP (Skinny Call Control Protocol) - Skinny gateways are a series of digital gateways that include the DT-24+, the DT-30+, and the WS-X6608-x1 Catalyst voice module.

Connectivity: 

Connectivity Call Processing Cluster PSTN PSTN WAN Call Processing Cluster Switch Switch PSTN – Public Switched Telephone Network

How can I check my Internet connection?: 

How can I check my Internet connection?

Typical Application QoS Requirements: 

Voice Data Bandwidth Low to Moderate Moderate to High Random Drop Sensitive Low High Delay Sensitive High Low Jitter Sensitive High Low Typical Application QoS Requirements

Firewall and NAT Refresher: 

Firewall and NAT Refresher Connection requests Connection replies Connection Table Connection Connection Connection Connection Connection Connection Connection Connection Network Address Translation (Overloading)

Why do firewalls or NAT cause problems?: 

Why do firewalls or NAT cause problems? With H.323, SIP and SCCP heavily use dynamically allocated ports Egress is ok, but igress is not

Why is QoS Important?: 

Why is QoS Important? In an Agency Network QoS: Ensures that real-time traffic gets priority Ensures that ERP/business-critical traffic is serviced appropriately Ensures that non-critical traffic (Napster, Gnotella, etc.) does NOT consume valuable bandwidth Protects against denial of service attacks!

Packet Labeling - Layer 3: 

Packet Labeling - Layer 3 3 bits = 8 values; 0-7 6 bits = 64 values; 0-63

VoIP and Video Demonstration: 

VoIP and Video Demonstration Cisco IP Phone Configuration Unity Call Manager Express on Cisco 3825 (gateway) IP Phone – 7960 and 7920 Call and Analysis Video End-points TANGBERG 1500 D-Link DVC-1000