Enabling students to stay connected
IIT-Kharagpur has set up a converged IP network throughout
its campus and introduced a host of applications to make education a fulfilling
experience for its students
The Indian Institute of Technology-Kharagpur (IIT-K) wanted to deliver educational
content to its students in a more flexible and organised manner, and decided
to use IT as the enabler. With the assistance of its alumni, the institute set
up a campus-wide converged IP network with over 4,000 access points that cover
every hostel room.
The network offers multi-layered switched QoS, video-on-demand, multicast video,
and the ability to host IP telephony in the future. The new multimedia-friendly
network gives the 5,000 students on the campus unrestricted access to the network
from their rooms without the need to be physically present at specific locations.
One of the most reputed educational institutes in India, IIT-K recognises that
information networks have emerged as strategic assets, and are a critical element
for delivering education and services. The institute felt the need to provide
state-of-art IP networking which could enhance the quality of the educational
The objectives were to deliver live lectures and screen events with the help
of IP multicasting, deliver high-quality video-on-demand to students hostels
without affecting the network performance and bandwidth, standardise repetitive
courses through video-on-demand, and provide opportunities to students and staff
to pursue fields of individual interest in addition to standard course curriculum.
In a gesture of goodwill, the 2000-2001 alumni of IIT-K, many of whom are successful
professionals in Silicon Valley, decided to provide funds for networking the
student hostels on campus.
- The organisation: The Indian Institute
of Technology-Kharagpur is an old and prestigious institute that offers
education to students who aspire to be scientists and engineers.
- The need: The institute wanted to offer
its students access to a world-class network infrastructure, and deliver
educational content to its students in a more flexible and organised
- The solution: With help from its alumni,
the institute set up a campus-wide converged IP network with over 4,000
access points covering all the hostel rooms. The network offers multi-layered
switched QoS, video-on-demand, multicast video, and the ability to host
IP telephony in future.
- The benefits: The network has given 5,000
students on campus access to the network from their rooms. This promotes
self-education and learning, and allows choice of development in fields
of individual interest. It also provides access to the network without
the need to be physically present at a specific location.
The campus already had a network based on Ethernet and ATM technology. Untouched
by the network were 14 hostels in the campus. Each hostel is divided into two
parts with 14 to 16 wings in each part. Each wing has 32 to 48 rooms per floor.
There was a suggestion to have a common room in the hostel with network outlets
for all to share, but this would have created other problems since there were
a large number of students. Another idea was to build a large network that would
encompass all areas of the campus.
Planning and designing a network of this scale gave rise to a number of considerations
which had to be kept in mind. They were:
The type of applicationsthere were plans to offer applications such as
IP-TV through multicasting, video-on-demand, and mpeg2- and mpeg4-based live
speeches, events and lectures.
Size of contenteach presentation comprised rich audio and visual elements
and was as long as an hour. As a result, the size of each file was large.
Geographical spreadthe hostel buildings were spread over an area of 2.5
to 3 square kilometres.
Utilisation would be the heaviest in the evening after classes.
Based on these considerations, the network design had to accommodate a
robust backbone, high switching capacity, and strong load-balancing capabilities.
It had to offer QoS so that traffic in one VLAN would not affect traffic of
the other wing and the entire network, explained Prof S Kumar, Faculty
Member, Mechanical Engineering Department, IIT-K.
The network was segmented using VLANs to reduce collision of domains and broadcast
domains, and deploy QoS in terms of the applications. For instance, a
person working on a site for educational research or collaborative study should
be given higher traffic priority over an e-mail user or a music download,
says Kumar. This act of prioritisation does not restrict any network activity,
but simply increases the time taken by a job with a lower priority.
The plan also intended that the network would use established industry standards
and policies for the multiple VLANs and QoS to allow the best possible data
rates and least latency.
14 to 16 access VLANs have been deployed at each hostel for individual wings.
The network has been partitioned with smaller collision domains to provide high
availability of network resources. This allows streaming multimedia (such as
full frame mpeg-2 video lectures and distributed e-learning computing programmes)
to provide shared whiteboard, chat and video simultaneously for multiple rooms
at peak hours.
Two primary applications, video streaming and video-on-demand, were achieved
through Ciscos IP-TV solution. This solution provides the streaming audio
and video content at data rates up to 80 Mbps on mpeg-2 and mpeg-4 in both unicast
and multicast formats for the entire network. In-house e-learning content servers
have been developed at the institutes Centre for Educational Technology
using the mpeg-4 standard.
The IP-TV Solution
The IP-TV solution has three components: the broadcast server, the archive server,
and the control server.
A broadcast server helps to pre-plan the time of a broadcast to a select group.
For instance, all computer science students staying in different hostel rooms
can plan to attend a live lecture from an expert abroad at 7 pm. The broadcast
can be planned in such a way that the media will only be distributed to the
intended students in the multicast group at the specific time, automatically,
without any reduction in network performance.
If a student who has missed a class wants to refer to the lecture or the notes
given earlier, he can use the video-on-demand service for viewing the lecture.
Although the size of the content can be huge, the network will automatically
prioritise and balance load on the switches so that overall performance is unaffected.
The network uses content distribution managers to avoid effects of multiple
media applications running on the network. This works with the help of content
engines (at different locations) which push content to the nodes. Each hostel
has a content engine which accesses the content load kept at a central location.
The content is pushed from the central location to the content engine at the
edges, so when a request for any media arrives, the content is fetched from
the local content distributor. This avoids load on the backbone.
There are 200-odd servers which
converge to the core (8-10 Gbps capacity) of the network based on two
Catalyst 6500 switches
There are 200-odd servers which converge to the core (8-10
Gbps capacity) of the network based on two Catalyst 6500 switches. This is connected
to multiple distribution switches. Each hostel has a distribution switch, and
the entire switching capacity is around 32 Gbps.
The Gigabit Ethernet LAN uses cables from D-Link. The servers are load balanced
so that the same content can reside at multiple servers. If there is a request,
and the data resides on multiple servers, a logical algorithm is used to carry
the load across the switches to each desktop.
The network enables IIT-K to deliver a complete e-learning package comprising
various audio and video formats to be broadcast to classrooms and hostel rooms.
This has considerably enhanced the students academic activities and preparedness
for industry. Every student has access to lecture material and virtual classrooms,
and can conduct several projects and exercises online over the network. The
network is also designed to cater to the QoS requirements of IP telephony. In
future, the institute hopes to configure the network to enable students to make
voice calls on IP phones and soft IP phones within the campus.
The uniqueness is the scale and the range of applications. There are few
educational institutes that offer access to such media-rich applications to
their students, declares Kumar. Another remarkable feature is the plan
in terms of scalability design. If a new building or location is to be added,
a new switch can be simply plugged into the networkand the network will
auto-learn and configure itself a separate VLAN.