Telecom Basicsx - 707com.com

refereeoppositeNetworking and Communications

Oct 30, 2013 (4 years and 14 days ago)

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Telecom basics

Emmanuel
Etheve

Summary


Introduction


Ethernet


Internet Protocol


Services


Trouble Shooting


How works internet


Summary


Introduction


OSI Model


Physical Layer


Ethernet


Internet Protocol


Services


Trouble Shooting


How works internet



Introduction


OSI model

Data unit

Layer

Function

Host

layers

Data

7. Application

Network process to application

6. Presentation

Data representation, encryption and decryption,
convert machine dependent data to machine
independent data

5. Session

Interhost

communication, managing sessions
between applications

Segments

4. Transport

End
-
to
-
end connections, reliability and flow

control

Media

layers

Packet/Datagr
am

3. Network

Path determination and logical

addressing

Frame

2. Data

link

Physical

addressing

Bit

1. Physical

Media, signal and binary transmission

Introduction


OSI model

Layer

Protocols

7. Application

HTTP, HTTPs, FTP, BOOTP, DNS, SSH, SMTP, POP3, IMAP

6. Presentation

ASCII, JPEG, TIFF, GIF

5. Session

NFS, SMB,

4. Transport

TCP, UDP, AH, ESP, GRE

3. Network

MPLS
, Frame
Relay,
IPv4
, IPv6, IGMP
, BGP
, RIP, OSPF, ICMP

2. Data

link

ARP, RARP, 802.11, 802.16
, PPP, L2TP, STP, Ethernet

1. Physical

DSL
, ISDN, RS
-
232, SDH, SONET

Introduction


Physical layer




SDH


ATM


DSL

Summary


Introduction


Ethernet


Introduction


Devices


Switching


Internet Protocol


Services


Trouble Shooting


How works internet


Ethernet


Introduction



Standard


Frame

10BASE
-
T: 10Mbps

100BASE
-
T: 100Mbps

1000BASE
-
T: 1Gbps

10GBASE
-
T:
10Gbps

Ethernet


Devices

Hub

Switch

Router

Ethernet


Switching

Ethernet


Practice

root password: Altran2012

Summary


Introduction


Ethernet


Internet Protocol


What is an IP address


Subnetting


Routing


Services


Trouble Shooting


How works internet


Internet Protocol


What is an IP address


Unique ID


Interconnect networks


32bits based in IPv4


128bits based in IPv6


Internet Protocol


Subnetting


Smaller networks


Uses a mask

Mask:
255
.
255
.
255
.192

CIDR: /26 S
H

Bit:
11111111
.
11111111
.
11111111
.11
000000

Subnet # = 2^S where S is subnet bits count

Host # = 2^H
-
2 where H is host bits count

Internet Protocol


Routing

[
root@linux

hack]#
route

n

Kernel IP routing table


Destination Gateway
Genmask


Flags Metric Ref
Use
Iface


203.106.93.64
*


255.255.255.224 U 0 0 0
eth0


10.2.0.0


*


255.255.0.0 U 0
0

0
eth1


10.3.0.0


10.2.0.2 255.255.0.0 UG 0 0 0 eth1


10.6.0.0


10.2.0.2 255.255.0.0 UG 0 0 0 eth1


10.7.0.0


10.2.0.2 255.255.0.0 UG 0 0 0 eth1

10.4.0.0


10.2.0.2 255.255.0.0 UG 0 0 0 eth1


10.5.0.0


10.2.0.2 255.255.0.0 UG 0 0 0 eth1

10.10.0.0


10.2.0.2 255.255.0.0 UG 0 0 0 eth1

10.8.0.0


10.2.0.2 255.255.0.0 UG 0 0 0 eth1

169.254.0.0

*


255.255.0.0 UG 0 0 0 eth1

10.9.0.0


10.2.0.2 255.255.0.0 UG 0 0 0 eth1

default


203.106.93.93
0.0.0.0


UG 0 0 0 eth0



Internet Protocol


Practice

Summary


Introduction


Ethernet


Internet Protocol


Services


Transport layer


Application layer


Security


Availability and accounting


Trouble Shooting


How works internet


Services


Transport layer




TCP Header





UDP header

Services


Application layer


Services


Security

Services


Availability and accounting

Services


Practice

Summary


Introduction


Ethernet


Internet Protocol


Services


Troubleshooting


Connectivity


Routing


Service availability


How works internet


Troubleshooting


Connectivity


Ping


Check the connectivity between 2 hosts


Result of the command:


ping

66.230.200.16

Pinging

66.230.200.16 avec 32 octets de données :

Réponse de 66.230.200.16 : octets=32 temps<10ms TTL=255

Réponse de 66.230.200.16 : octets=32 temps<10ms TTL=255

Réponse de 66.230.200.16 : octets=32 temps<10ms TTL=255

Réponse de 66.230.200.16 : octets=32 temps<10ms TTL=255

Troubleshooting


Connectivity


Traceroute


Check the patch between 2 hosts


Result of the command:


traceroute

fr.wikipedia.org

traceroute

to rr.knams.wikimedia.org (145.97.39.155), 30 hops max, 38 byte packets


1 80.67.162.30 (80.67.162.30) 0.341
ms

0.300
ms

0.299
ms


2 telehouse2
-
gw.netaktiv.com (80.67.170.1) 5.686
ms

1.656
ms

0.428
ms


3 giga.gitoyen.net (80.67.168.16) 1.169
ms

0.704
ms

0.563
ms


4 62.4.73.27 (62.4.73.27) 2.382
ms

1.623
ms

1.297
ms


5 ge5
-
2.mpr2.cdg2.fr.above.net (64.125.23.86) 1.196
ms

ge9
-
4.mpr2.cdg2.fr.above.net (64.125.23.102) 1.290
ms

ge5
-
1.mpr2.cdg2.fr.above.net (64.125.23.82) 30.297
ms


6 so
-
5
-
0
-
0.cr1.lhr3.uk.above.net (64.125.23.13) 41.900
ms

9.658
ms

9.118
ms


7 so
-
7
-
0
-
0.mpr1.ams5.nl.above.net (64.125.27.178) 23.403
ms

23.209
ms

23.703
ms


8 64.125.27.221.available.above.net (64.125.27.221) 19.149
ms

so
-
0
-
0
-
0.mpr3.ams1.nl.above.net (64.125.27.181)
19.378
ms

64.125.27.221.available.above.net (64.125.27.221) 20.017
ms


9 PNI.Surfnet.ams1.above.net (82.98.247.2) 16.834
ms

16.384
ms

16.129
ms

10 af
-
500.xsr01.amsterdam1a.surf.net (145.145.80.9) 21.525
ms

20.645
ms

24.101
ms

11 kncsw001
-
router.customer.surf.net (145.145.18.158) 20.233
ms

16.868
ms

19.568
ms

12 gi0
-
24.csw2
-
knams.wikimedia.org (145.97.32.29) 23.614
ms

23.270
ms

23.574
ms

13 rr.knams.wikimedia.org (145.97.39.155) 23.992
ms

23.050
ms

23.657
ms

Troubleshooting


Connectivity


nslookup


Resolve a FQDN into an IP address


Result of the command:



nslookup

www.wikipedia.org


Serveur : dns1.proxad.net


Address
: 212.27.40.240




Réponse ne faisant pas autorité :


Nom : rr.esams.wikimedia.org


Address
: 91.198.174.2


Aliases
: www.wikipedia.org


rr.wikimedia.org

Troubleshooting


Routing


Route:


Manipulate routing table


route
-
n

Kernel IP routing table

Destination Gateway
Genmask

Flags Metric Ref Use
Iface

192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0

0.0.0.0 192.168.1.10 0.0.0.0 UG 0 0 0 eth0


route add default
gw

192.168.1.10


route add
-
net 192.168.1.0
netmask

255.255.255.0
gw

192.168.1.10

Troubleshooting


Service availability


Netstat


Provide information on active connections



netstat


Connexions

actives


Proto
Adresse

locale
Adresse

distante

Etat


TCP SRVX:1922
rr.knams.wikimedia.org:http

ESTABLISHED


TCP SRVX:1924
rr.knams.wikimedia.org:http

ESTABLISHED

Troubleshooting


Practice

Summary


Introduction


Ethernet


Internet Protocol


Services


Trouble Shooting


How works internet


Minimum requirement


NAPT


Services


How works internet


Minimum requirement


IP address:


usually assigned via a DHCP server within a private pool


Subnet mask:


which determine to which network the machine belongs


Gateway:


this is where the packet should be send to access the
Internet


DNS server:


to provide the remote server IP to the requested hosts,
they are usually two of them defined.


How works internet


NAPT

How works internet


Services






HTTP
:
HyperText

Transfer Protocol, used to access web pages on the internet. It uses the port 80


HTTPs: secured HTTP, used to access secure content on the internet. It uses the port 443


SMTP: Simple Mail Transfer Protocol, used to exchange emails. It uses port 25


IMAP: Internet Message Access Protocol, used to exchange emails. It uses port 143


POP3: Post Office Protocol, used to exchange emails It uses port 110


FTP: File transfer protocol, used to send file from a client to a file server. It uses port 21 and 20


TELNET:
TELecommunications

NETwork
, used to remotely access a machine in text mode It uses port 23


SSH: Secure Shell, used to take the remote control of a machine in text mode. It uses port 22


DNS: Domain Name Server, used to resolve the server name into an IP address: it uses port 53


DHCP: Dynamic Host Configuration Protocol, used to assign IP address to hosts. It uses port 67


How works internet


Practice

Thank you for you attention


Questions ?