Managing Internet Bandwidth: Experience in Faculty of Industrial Technology, Islamic University of Indonesia – Mukhammad Andri Setiawan
ISSN 1858-1633 2005 ICTS 39
used on the Web, and can provide bandwidth savings of up to 40 [1].
After the initial download of the resource the users do not have to compete for bandwidth on what is
likely to be a slow and congested external network path. Instead, users will get a copy of the resource
delivered rapidly to them from a local cache server over what will normally be a much faster and less
heavily loaded internal institutional network connection.
A hierarchy of caches may be used to increase the effective cache size and thus improve the hit rate.
Push caching attempts to place content in a cache before it is requested, either by looking at other
caches, or by predicting usage. Some of these techniques are discussed by Dias 1996 in his
research paper in title “A Smart Internet Caching System” as described in [1].
In Faculty of Industrial Technology, Islamic University of Indonesia, we do serve the Internet
access by using the Squid proxy server. Squid proxy server is used to cache web pages that have been
accessed recently. Squid is implemented as a transparent proxy at the central cache server,
therefore, users are automatically served by the proxy for all web access without any browser configuration.
4.2 Access List
Faculty of Industrial Technology is an academic institution. We realize that, most of Internet access
should be addressed into academic needs, and should not intended to fulfill needs on leisure such as
networking games, peer to peer program such as napster, e donkey, grokster, or bit torrent, and adults
sites, and ads. Here, we define access lists that will control user, which site they can visit and which one is
not.
We also combine access list and firewall in PC router to disable some common port that is used to run
some spyware program. Figure 2 show access list that is implemented in our server.
acl notsex url_regex -i etcsquidnotsex acl sex url_regex -i etcsquidsex
acl utara src 192.168.100.024 acl ftinetwork dst 202.150.76.20029
http_access always_direct allow ftinetwork
http_access allow notsex all http_access deny sex all
http_access allow utara
Figure 2. Access list configuration file
As a result, users who try to access site that is prohibited in our access list will get an error message.
4.3 Quality of Service QoS
To provide a good link connection, sometimes a network manager may wish to offer different levels of
service for different subsets of the traffic passing over the infrastructure. The QoS technologies allow the
manager to do this. The service levels that QoS deals with include
dedicated bandwidth, reduced packet loss, controllable amounts of jitter and latency and ensure that particular
traffic flows do not swamp the network and drown out other flows. These facilities can help ensure that
critical traffic is delivered more reliably [2]. The QoS systems operate only in real-time, in response to the
traffic. They do not generally attempt to manage traffic over a longer term. Also, QoS systems
normally operate in an environment where the total bandwidth requirement of high-priority traffic is less
than the available bandwidth. If high-priority traffic approaches or exceeds the available bandwidth,
performance degrades rapidly [1].
To make use of QoS, packets in flow need to be identified, classified and then marked. The
identification and classification of packets is performed as described above for traffic shaping,
either by source, destination and ports or by using application level probing into the packet contents [2].
In Faculty of Industrial Technology, we manage QoS especially at wireless networking. As we
provided free hotspot areas, we must provide a guarantee that the academic staffs still have a good
link quality even a numerous wireless user is connecting to our hotspot areas. We provide QoS well
so that our bandwidth doesn’t run out quickly because of the use of WiFi devices in our free hotspot areas.
The objective of much work on Quality of Service QoS is to provide desired levels of throughput,
delay, etc. in the face of unreliable networks and congestion. In wireless networking especially for the
free hotspot areas, we provide a low priority to all services, including HTTP, FTP, POP3, SMTP and a
few ports that commonly used in Internet. It means that all services will be treated as a lower level priority
if there are other activities that is using those services but not using the free hotspot connections. If the
priority is set to lower, a lower speed will impact; hence our bandwidth isn’t grabbed out by wireless
connections. The free hotspot areas will have its high priority back if the other connection is not using those
services.
4.4 Rate Limiting
