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Internet Exchangesand Routing - APAN's Persepctive -

Internet Exchanges and Routing
- APAN's Persepctive -

Kilnam Chon
KAIST, Korea
APAN Chair

1. Introduction

Asia Pacific Advanced Network(APAN) was formed in 1997.[1,2,3]  APAN is one of
the second generation Internet for research and education community like
Internet 2 in USA[4], CA*net 2, 3, 4 in Canada[5], and TEN 155 in Europe[6].

APAN network was formed to provide high performance network to the research 
and education community in Asia-Pacific region through appropriate network
design such as the Internet exchange points and access points, efficient
routing, quality of service, performance measurement and tuning, and so on.

Three Internet exchange points were set up in Tokyo, Seoul and Singapore
in addition to STAR TAP in Chicago, which is operated by Internet 2 Community
in USA.  These three exchange points provide Layer 2 connections as well as
Layer 3 connections.  All three exchange points and STAR TAP were fully
connected to provide efficient routing. The routing is fairly simple in
APAN.  Usually, packets are routed to one of the three exchange points, then
forwarded to the relevant exchange point, or to the destination access
point, or the gateway of another network.  Some of the link has specific
AUP to prohibit certain types of traffic such as commercial traffic.
See Figure 1 for the current network configuration of APAN.

Quality of service could be provided based on DiffServe, or allocation of
PVC to specific applications.  DiffServe is working reasonable well such 
as the video conferencing between Tokyo in Japan and Daejeon in Korea 
during the recent KOREN Workshop. 

Performance measurements on delay, throughput, and other factors are done
at all exchange points as well as some access points.  Performance tuning
based on these measurements are done, in particular across the Pacific.

2. Regional and National Internet Exchanges

Through our experience of APAN, and other first and second generation
Internets,  we agree that we need one or more neutral national Internet
exchange point which must be operated in transparent manner.  STAR TAP
and APAN Tokyo Exchange Point are the notable examples of such neutral
transparent exchange points, but they are for research and education
community and not for the whole Internet community.

Many countries have one or more Internet exchanges in their countries.
Some of them are operated by ISPs, and others are operated by public
organizations.  The former do not offer neutral exchanges.  The latter
tend to be inefficient due to nature of non-commercial service.  The most
important factor for the Internet exchanges is service quality.  Many
Internet exchanges are of poor quality throughout the world. 

Private peering is also very common due to various reasons; lack of
Internet exchange, lack of neutral Internet exchange, lack of broadband
Internet exchange, and so on.  One extreme case is that two major ISPs
in Korea have private peering with capacity of 10 Gbps between them.

In many Asian countries, there is strong demand to have one or more efficient,
and neutral Internet exchange in their countries, and they may be operated
by a consortium to guarantee neutrality and transparency.  We may need
good collaboration among these exchanges for connectivity, network
engineering, and so on.  We need to come up with some scheme to provide
acceptable service quality, which is often lacking anywhere in the world.
Some of the national Internet exchanges may function as regional Internet
exchanges.  Candidate locations would include Tokyo, Seoul, Beijing,
Hong Kong and Singapore.  The one in Tokyo is coming close to such a
neutral regional Internet exchange.[8]

3. Broadband Access for Next Generation Internet

Broadband accesses beyond dialup and ISDN are some of the hot issues 
lately.  There are two categories for the broadband access; electric
wires, and optical fiber.  The electic wires include cable modem and
twisted pair for DSL.  They typically offer fraction of mbps to
several mbps.  The optical fiber offer 10 mbps to 1 gbps.

The broadband access using the cable modem and DLS took off in Korea
with 40% of the household, or over 80% of the Internet users access
using these services now with USA next with around 10%, and others
less than 10%.  Watching television program through the Internet
is common practice in Korea now.

The broadband access using the optical fiber is yet to come.  There are
numerous experiements going on around the world.  Canada and Sweden
among others started offering large scale services[3, 9] with typically
capacity of 100 mbps with occasional 1 gbps.  Japan plans to offer
the optical fiber access with 10 and 100 mbps in 2001.

With broadband access becoming increasing common, in particular in Asia,
we need to be ready with good backbone networks and the Internet exchanges.
The demand on capacity and performance at these networks and exchanges
would be great, and we should be ready for acceptable services.

4. Future

All next generation networks for research and education community in the
world are heading for optical Internet with ever increasing bandwidth.
Canada is leading in this technology by offering CA*net 3 and CA*net 4.
USA is coming up with STAR LIGHT, the Internet exchange for optical
interconnect.  Europe is following with similar network plans, too.
In Asia, APAN and others need to upgrade their networks similarly.
This is particularly true since many national research and education
networs are becoming optical Internet with typical capacity of 1 to 10
gbps for access and backbone, and the international networks such as APAN
has to handle multiple gbps traffic.  This would be the challenge for the
coming years for APAN.


1. Kilnam Chon, Asia-Pacific Advanced Network, Presentation Material,, 2001.
2. Bu-Sung Lee and CY Wong(Ed.), APAN Documentation, 2000.
3. APAN Secretariat,, 2001.
4. Internet 2 Secretariat,, 2001.
5. CANARIE,, 2001.
6. DANTE,, 2001.
7. STAR TAP,, 2001.
8. WDE Project, Network Service Provider Internet eXchange Project(NSPIXP),, 2001.
9. Stokab,, 2001

Figure 1. APAN Map