Solwise SAR715PV ADSL Ethernet Router User’s Guide
Chapter
6
. VPN Configuration
93
Site to Site VPNs
Traditionally, connecting two branch offices of the same company
required leasing a dedicated private circuit or a frame relay
permanent virtual circuit (PVC) between two locations. By using
virtual private networking (VPN) to link two offices together, as show
above, can offer considerable savings, while offering a competitive
alternative to leased lines or PVCs.
Basic Terms and concepts
•
VPN Tunnel
: VPN tunnels are created from site to site pair and
secure encrypted connection between two points thru a public or
third party network.
•
Encryption
: The process of scrambling data in such way that it is
not readable by anyone except the intended recipient and only after
it has been properly decrypted.
•
Authentication
: Before any communication can be called private,
each party must know the identity of the other. The same holds true
for secure network communication: One network system must
make sure that the other network system is the intended
correspondent. The process of such identity verification is called
authentication.
•
Time to live
: The time to live (TTL) field indicates the maximum
amount of time this IP packet is allowed to remain in the network.
Each router is required to decrement this value as it routes the
packet. The packet is dropped if this value reaches 0.
•
Digital Signatures
: Is the electronic analogy to a handwritten
signature, and in many ways it is an even stronger device. The key
is shared by at least one other party.
•
IKE
: IKE is a protocol negotiation and key exchange protocol that
is part of the IPSEC protocol suite specified by the Internet
Engineering Task Force (IETF). IKE allows communicating parties
implementing VPNS to automatically negotiate IPSEC SAs to
facilitate the implementation of VPNs. With IKE, a separate IKE SA
is initially created to provide a secure channel for negotiating an
IPSec SAs to facilitate the implementation of VPNs.
•
Point-to-Point Protocol (PPP)
: A standardized Internet
encapsulation of IP over point-to-point links. 25
Virtual Private Networking Configuration Guide
•
Point-to Point Tunneling Protocol (PPTP)
: A Microsoft-
sponsored IETF draft standard for implementing VPNs form the
Windows 95/98 operating system to a VPN gateway.
•
Private Key
: A digital key code used to decrypt data and verify
digital signatures. This key is kept secret, and is known only to its
owner.
•
Public key
: A trusted and efficient key and certificate
management system.
