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Addressing in Telephone Networks &
IP Networks
INFOTECH Seminar Advanced Communication Services
SS 2003
July 3, 2003
Name: Xiangting Bi
Mentor: Dr. Stephan Rupp
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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:
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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
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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 PerspectiveAgenda
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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
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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
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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 software00/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.deINFOTECH_ASC_Seminar_Template.ppt
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3.E.164 number 00 addressing in Tel. network
E.164 00nbsp; international public telecommunication numbering planmade 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 usedINFOTECH_ASC_Seminar_Template.ppt
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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
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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;
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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
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Benefits of ENUM00/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)
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5.Conclusion and Perspective
Conclusion00ENUM 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.
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Perspective00/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
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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
