long-distance dial-up connection
3
Figure 7-9 A WAN using frame relay
4
A BRI link
A PRI link
5
CSU/DSU
point-to-point T-carrier connection
T-carrier connecting to a LAN through a router
6
DSL connection
7
SONET ring
8
 Virtual
Private Network is a type of private
network that uses public
telecommunication, such as the Internet,
instead of leased lines to communicate.
 Became
popular as more employees worked
in remote locations.
(From Gartner Consulting)

Secure VPNs use cryptographic tunneling
protocols.
◦ IPsec, SSL/TLS, OpenVPN, PPTP, L2TP, L2TPv3, VPNQ and MPVPN

Trusted VPNs rely on the security of a single
provider’s network to protect the traffic.
◦ MPLS and L2F
A virtual point-to-point connection
made through a public network. It transports
encapsulated datagrams.
Original Datagram
Encrypted Inner Datagram
Datagram Header
Outer Datagram Data Area
Data Encapsulation [From Comer]
Two types of end points:
 Remote Access
 Site-to-Site
Figure 1
Authentication – validates that the data was sent from the
sender.
 Access control – limiting unauthorized users from
accessing the network.
 Confidentiality – preventing the data to be read or copied
as the data is being transported.
 Data Integrity – ensuring that the data has not been
altered


Cryptography Technic
Encryption -- is a method of “scrambling” data before
transmitting it onto the Internet.
Public Key Encryption Technique
Digital signature – for authentication


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VPN can be deployed in three ways :
Host to host
Site-to-Site
Host-to-Site



Remote access VPN
Intranet VPN
Extranet VPN

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
MPLS = Multi Protocol Label Switching
Suatu metode forwarding (meneruskan data/paket
melalui suatu jaringan dengan menggunakan informasi
label yang dilekatkan pada I
Memungkinkan router meneruskan paket dengan hanya
melihat label yang melekat pada paket tersebut,
sehinggap tidak perlu lagi melihat alamat IP tujuan)
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
Perpaduan mekanisme Label Swapping (Layer
2) dan Routing (Layer 3)
Terdiri atas LSR yang saling terhubung,
membentuk suatu LSP
LSR pertama disebut ingress
LSR terakhir disebut egress
Bagian tepi dari jaringan LSR disebut LER
Back
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
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LSR = Label Switched Router
LSP = Label Switched Path
LER = Label Edge Router
TTL = Time to Live
Back
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
Pembuatan label dan distribusi
Pembuatan label dalam tiap router
Pembuatan jalur label yang terhubung
Pemasukan label
Forwarding paket
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