VCCS colleges are heavily involved with providing instruction between and among campuses. Research of emerging technologies has brought several tools to the forefront that will provide for future distance learning initiatives. Cisco’s IP/TV® version 3 streaming media solution, which is developed on the Microsoft® Windows Media™ Technologies platform, provided an option for expanding the distance learning technical infrastructure environment. The pairing of Cisco and Microsoft technologies with the VCCS instructional expertise provides the most comprehensive and flexible solution for using streaming media to deploy media-intensive business and distance learning applications, for a wider range of desktop computer customers on IP networks. This new technology will help increase productivity and reduce costs while reaping an increased customer base.

The products tested support a media presentation platform with quality of service and network management tools for IP available. This business solution is viable to build a scaleable Distance Learning infrastructure to supplement current technology. IPTV is standards-based which enables essential multi-vendor solutions critical for success in the Internet economy.

The VCCS pilot utilized two installations of the IPTV products. J.Sargeant Reynolds elected to install the Cisco hardware solution with software pre-configured, whereas New River selected the server hardware from a competing vendor, installed and configured IPTV. The following hardware and software is installed at both broadcast locations. Receive only locations installed the client portion, lan switch and router.

• The Cisco IP/TV broadcast server captures and multicast the live class and prerecorded for later viewing on demand. The VCCS implemented Cisco IP/TV servers using MPEG-1 as the primary format.

• The Cisco IP/TV control server manages the video as deployed on a separate network.va subnet. Though not currently implemented, the server software is capable of controlling bandwidth usage, distribution of content to remote servers, scheduling broadcasts and monitoring server activity. It is capable of also selecting the best video server in proximity to the viewer for greater network control in larger deployments.

• Cisco IP/TV archive server, with a storage capacity of 120 hours, is used for supporting video-on-demand.

• The customer has the Cisco IP/TV Viewer, which provides a program listing of all class offered. Once a course is selected, a application id and password must be entered. The IP/TV viewers are directed to the appropriate broadcast server to optimize network efficiency. Both New River and J.Sargeant Reynolds are configured as broadcast locations.

These switches have up to 25 10BaseT switched Ethernet ports (including the AUI switch port on the back panel), each port providing users or groups of users dedicated 10-Mbps bandwidth to resources within the network. These ports connect to other 10BaseT-compatible devices, such as single workstations and 10BaseT hubs. The switches also have two 100BaseT switched ports for delivering maximum performance to high-speed servers and to backbone switches and routers.

The VCCS pilot also utilized the Cisco 3640 to integrate video, voice and data over the Intranet connecting the five participating sites. This device delivers a solution that includes management and quality of service tools for the LAN/WAN. The 3600 series high-performance, high-density dial access, advanced LAN-to-LAN routing, multiservice voice, video, and data integration, and a growing list of available interfaces make this a versatile platform with the power to grow comfortably in the future.

H.323 Client Support

The capability to support a multi-homed server will allow H.323 client SDP listening to participate in programs or recordings.

The IPTV pilot was tested across the college local campus network and Network.Va (a statewide broadband network).

IP Multicast

The VCCS IPTV application is based on IP multicast. There are several aspects to handling multicasts effectively in the pilot:

• Multicast routing, Protocol Independent Multicast (PIM) dense mode and sparse mode
• Pruning multicast trees with Cisco Group Multicast Protocol (CGMP) snooping
• Switch and router multicast performance
• Multicast policy

The industry standard preferred routing protocol for multicast is PIM. PIM sparse mode is described in RFC 2117, and PIM dense mode is on the standards track. PIM is being widely deployed in the Internet and on intranets. As its name suggests, PIM works with various unicast routing protocols such as OSPF and Enhanced IGRP. PIM routers are able to interact with the Distance Vector Multicast Routing Protocol (DVMRP). DVMRP is a legacy multicast routing protocol deployed in the Internet multicast backbone (MBONE). Currently 50 percent of the MBONE has converted to PIM, and it is expected that PIM will replace DVMRP over time.

PIM can operate in dense mode or in sparse mode. Dense-mode operation is used for IPTV where there is a multicast server with many clients throughout the campus. PIM builds efficient multicast trees that minimize the amount of traffic on the network. This is particularly important for high-bandwidth applications such as real-time video. In most environments, PIM is configured as sparse-dense and automatically uses either sparse mode or dense mode as required.

Another protocol that will be utilized as the project is scaled is IGMP, which is used by multicast clients and servers to join or advertise multicast groups. The local gateway router makes a multicast available on subnets with active listeners, but blocks the traffic if no listeners are present. CGMP extends multicast pruning down to the Catalyst switch. A Cisco router sends out a CGMP message to advertise all the host MAC addresses that belong to a multicast group. Catalyst switches receive the CGMP message and forward multicast traffic only to ports with the specific MAC address in the forwarding table. This blocks multicast packets from all switch ports that don't have group members downstream.

The multilayer design model used in this pilot is inherently scalable. Layer 3 switching performance scales because it is distributed. Backbone performance scales as you add more links or more switches. The individual switch domains or buildings scale to over 1000 client devices with two distribution-layer switches in a typical redundant configuration. More building blocks or server blocks can be added to the campus without changing the design model. Because the multilayer design model is highly structured and deterministic, it is also scaleable from a management and administration perspective.

The VCCS will be testing Intelligent Layer 3 routing protocols, such as OSPF and Enhanced IGRP, that handle path determination and load balancing over multiple paths in the backbone. OSPF overhead in the backbone rises linearly as the number of distribution-layer switches rises. This is because OSPF elects one designated router and one backup designated router to peer with all the other Layer 3 switches in the distribution layer.

Pricing and Availability

Cisco IP/TV Viewer is free with the current 3.0 release.

The industry-leading SMARTnet maintenance service and support program backs Cisco IP/TV. More information about Cisco IP/TV and a free demo CD-ROM can be found at http://www.cisco.com/go/iptv.