>
INFOTECH_ASC_Seminar_Template.ppt
Page: 1
Addressing
in Telephone Networks &
IP Networks
INFOTECH Seminar Advanced
Communication Services
SS 2003
July
3, 2003
Name:
Xiangting Bi
Mentor: Dr. Stephan
Rupp
INFOTECH_ASC_Seminar_Template.ppt
Page: 2
Motivation: What does
Addressing concerned in Networks ?
Servers, Mobile
Sets, Telephone Sets, PCs 00/i>
IP-Networks
or
Telephone
Networks:
How
do devices
connect
each other?
How
can services
be
addressed?
Devices:
Call,
Fax, Email, VoIP, Web browse ...
Services:
INFOTECH_ASC_Seminar_Template.ppt
Page: 3
Solved Questions
How is addressing of
devices and services solved in
telephone networks?
IP networks?
How do telephone networks
and IP networks interwork?
What kind of solution does
ENUM provide?
What ENUM applications
for addressing can we expect in the future?
INFOTECH_ASC_Seminar_Template.ppt
Page: 4
1. URL 00IP networks
2. DNS 00IP networks
3. E.164 Number 00Telephone
networks
4. ENUM 00driving the
convergence of two networks
Concept of ENUM
How ENUM enables convergence
Benefits of ENUM
5.Conclusion and Perspective
Agenda
INFOTECH_ASC_Seminar_Template.ppt
Page: 5
1.URL 00/b> addresses
of IP network
URL 00/b> Uniform
Resource Locators
URL is a compact string that
represent for a resource available on Internet , it is used to 00ocate00
resources.
General Syntax of URL:
<scheme>:<scheme-specific-part>
00 <scheme>
00ftp, http, mailto, telnet and etc.
00/font> <scheme-specific-part>: its interpretation
depends on the scheme
URL syntax of HTTP scheme 00/b> http://<host>:<port>/<path>?<searchpart>
00nbsp; a
hierarchy structure can be used
For example:
00http://hotwired.lycos.com/webmonkey/96/53/index0a.html?tw=authoring
INFOTECH_ASC_Seminar_Template.ppt
Page: 6
2.DNS 00addressing
in IP network
DNS 00
Domain Name System
DNS is a global network of
servers to translate
host names/domain names into IP addresses:
www.hotmail.com 00/b>> 207.68.172.239
Domain Name Space Tree
00/font> Top-Level Domain names :
00/font> Generic: .EDU, .COM, .NET, .ORG, .GOV,
.MIL, and .INT
00/font> Country
Code: .US, .DE, .FR, .CA ...
00/font> .ARPA:
specific name domain allocated for ENUM
00/font> Each domain00
information is stored in
a corresponding
name server
INFOTECH_ASC_Seminar_Template.ppt
Page: 7
2.DNS 00lookup process
in IP network
DNS exits on name servers
all over the world, known as a distributed database
A DNS Server is just a computer
on which running the DNS software
00/font> DNS software
comprises two elements: name server and resolver
00/font> name server
: host
name to IP address / addresses of subdomain
00/font> resolver
: asking other name server farther up the tree for help
Hierarchy
structure of domain name is used
for lookup: www.google.de
INFOTECH_ASC_Seminar_Template.ppt
Page: 8
3.E.164 number 00
addressing in Tel. network
E.164 00nbsp;
international public telecommunication numbering plan
made by International Telecommunication Union (ITU).
E.164 number 00
explain in sample way, is telephone
number we used everyday.
CC: country
code (n=1~3 digitals)
NDC: national destination code
SN: subscriber number
NSN: national significant number
(max 15- n digitals)
Three Categories of
E.164 number:
00nbsp; National
telephone services
00nbsp; Global
telephone services
00/font> International
networks
National telephone services : most popular, most often used
INFOTECH_ASC_Seminar_Template.ppt
Page: 9
3.E.164 number 00
addressing in Tel. network
An example: +49
711
5078245
|
|
|
CC NDC
SN
00/font> "+"
represents the international access code or prefix, e.g., 0049.
00/font> in Germany, call 0711- 5078245; outside Germany,
call 0049-711- 5078245
00/font> the similar structure
to domain name
space tree
E.164 Number Tree :
INFOTECH_ASC_Seminar_Template.ppt
Page: 10
4.ENUM 00driving
the convergence
Concept of ENUM:
ENUM is the protocol that translate
a complete, international telephone number into a specific domain name
address.
00This specific
domain name address is to be used by DNS
00/font>
How to translate?
1. Take the telephone number into a complete international number.
For example, 0711-507-8245 00gt; +49-711-507-8245.
2. Remove all characters except digits. For example, 497115078245.
3. Reverse the order of the digits. For example: 542870511794
.
4. Put dots "." between each digit. For example: 5.4.2.8.7.0.5.1.1.7.9.4
5. Append
the string ".e164.arpa" to the end.
For example: 5.4.2.8.7.0.5.1.1.7.9.4.e164.arpa
00nbsp; Structure
of .ARPA domain 00gt;
INFOTECH_ASC_Seminar_Template.ppt
Page: 11
4.ENUM 00driving
the convergence
How ENUM enables convergence
?
00nbsp; user
registers telephone
number for ENUM
services
00nbsp; the
registered services is saved
in Naming Authority Pointer
(NAPTR) Resource
Records
00/font>
NAPTR锕0/b>is stored
in DNS Server1
锕0/b>NAPTR
Form:
$ORIGIN 5.4.2.8.7.0.5.1.1.7.9.4.e164.arpa.
IN NAPTR 100 10 "u" "sip+E2U"
"!^.*$!sip:bob@sip.telebob.au!"
IN NAPTR 100 10 "u" "http+E2U"
"!^.*$!http://www. Bobhome .au"
00nbsp; Gateway
itself pickup correct
service and
domain name
00nbsp; IP
addresses of domain name
is stored
in DNS Server2
INFOTECH_ASC_Seminar_Template.ppt
Page: 12
Benefits of ENUM
00/font> the call is setup entirely over the Internet,
therefore taking
as little time, or even in less time,
as a call through PSTN.
00nbsp; Not
limited on Internet: if Internet
call connection is failed, it can open PSTN for connection.
00/font> Comparing to the traditional IP telephone technique,
which statically stores in each gateway itself with a list of
E.164 phone numbers and corresponding IP addresses, ENUM provides the dynamic mapping
from domain name to IP address 00/font>
update happens in DNS server instead of in gateway.
00nbsp; ENUM provides
possibilities of many new servises
that cannot be realized only by PSTN or Internet. ENUM enables us using
one telephone number to :
4.ENUM 00driving
the convergence
00browse
web page
00/font> send
email
00/font> send
fax
00MSN chat
00send
fax as an email / send an email to fax machine
00forward
call to another phone / voice email in case of no one anwser
00.......(using
you rich imagination)
INFOTECH_ASC_Seminar_Template.ppt
Page: 13
5.Conclusion and Perspective
Conclusion
00ENUM
drives the convergence of PSTN and IP networks
00/font> ENUM privides
single point of contacting for all services. "one-number for everything".
00if an application exists on the Internet, it
can probably be mapped to a telephone number
and reached using ENUM.
00ENUM utilizes existing numbering resources and
DNS database, it does not change any
administration and does not drain already scarce number and IP resources
in PSTN and
Internet.
00With ENUM, user still has to remember boring
telephone numbers. This can be improved by storing list of name information
to corresponding telephone number in telephone. Then only names needs
to be remember.
INFOTECH_ASC_Seminar_Template.ppt
Page: 14
Perspective
00/font> Potential
of this fascinating ENUM technique is still not exhausted.
00nbsp; As an evolving architecture, ENUM will persistently
provide new services of PSTN and Internet convergence.
00/font> The
true time for ENUM is coming.
Once ENUM becomes widespread, it may well enable the greatest changes
to the Internet that we have yet seen.
00Problem: together with the great benrfits, ENUM
will also brings into another convenience to violate personal privacy
on the Internet 00/b> demand for privacy protection will become
intensive along with the widespread of ENUM.
5.Conclusion and Perspective
INFOTECH_ASC_Seminar_Template.ppt
Page: 15
ABBREVIATIONS
IP Network 00Internet Protocol
Network
PSTN 00Public Switched Telephone
Network
URL 00Uniform Resource Locators
DNS
00Domain Name System
TLDs 00Top-Level Domain names
ITU 00International Telecommunication
Union
VoIP
00b> Voice over IP
SIP 00Session Initiation Protocol
NAPTR RR 00Naming Authority
Pointer Resource Records
URI
00Uniform Resource Identifier
DHCP 00Dynamic Host Configuration
Protocol
Kein Folientitel
724k 
