user manual

AT-TQ2403 Management Software User's Guide 287
The Point-to-P
oint Protocol is a standard for transmitting network layer datagrams (IP packets) over serial
point-to-point links. PPP is designed to operate both over asynchronous connections and bit-oriented
synchronous systems.
PPPoE
Point-to-Point Protocol over Ethernet (PPPoE) is a specification for connecting the users on a LAN to the
Internet through a common broadband medium, such as a single DSL or cable modem line.
PPtP
Point-to-Point Tunneling Protocol (PPtP) is a technology for creating a Virtual Private Network (VPN)
within the Point-to-Point Protocol (PPP). It is used to ensure that data transmitted from one VPN node to
another are secure.
Proxy
A proxy is server located between a client application and a real server. It intercepts requests, attempting to
fulfill them itself. If it cannot, it forwards them to the real server. Proxy servers have two main purposes:
improve performance by spreading requests over several machines and filter requests to prevent access to
specific servers or services.
PSK
Pre-Shared Key (PSK), see Shared Key.
Public Key
A public key is used in public key cryptography to encrypt a message which can only be decrypted with the
recipient's private or secret key. Public key encryption is also called asymmetric encryption, because it uses
two keys, or Diffie-Hellman encryption. Also see Shared Key.
Q
QoS
Quality of Service (QoS) defines the performance properties of a network service, including guaranteed
throughput, transit delay, and priority queues. QoS is designed to minimize Latency, Jitter, Packet Loss, and
network congestion, and provide a way of allocating dedicated bandwidth for high priority network traffic.
The IEEE standard for implementing QoS on wireless networks is currently in-work by the 802.11e task
group. A subset of 802.11e features is described in the WMM specification.
R
RADIUS
The Remote Authentication Dial-In User Service (RADIUS) provides an authentication and accounting
system. It is a popular authentication mechanism for many ISPs.
RC4
A symmetric stream cipher provided by
RSA Security.
It is a variable key-size stream cipher with byte-
oriented operations. It allows keys up to 2048 bits in length.
Roaming