PAP sẽ gửi mật khẩu không được mã hóa và không cố gắng để xác minh xem người dùng có thẩm quyền để truy cập vào tài nguyên yêu cầu, nó chỉ đơn thuần xác định kết thúc từ xa. Xem thêm: tra tính chẵn Một phương pháp kiểm tra lỗi trong việc truyền tải dữ liệu. | Glossary 425 authentication request containing a password and ID to the local router when attempting to connect. Unlike the more secure CHAP Challenge Handshake Authentication Protocol PAP sends the password unencrypted and does not attempt to verify whether the user is authorized to access the requested resource it merely identifies the remote end. See also CHAP. parity checking A method of error checking in data transmissions. An extra bit the parity bit is added to each character or data word so that the sum of the bits will be either an odd number in odd parity or an even number even parity . partial mesh A type of network topology in which some network nodes form a full mesh where every node has either a physical or a virtual circuit linking it to every other network node but others are attached to only one or two nodes in the network. A typical use of partialmesh topology is in peripheral networks linked to a fully meshed backbone. See also full mesh. passive state Regarding an EIGRP routing table a route is considered to be in the passive state when a router is not performing a route convergence. PAT Port Address Translation This process allows a single IP address to represent multiple resources by altering the source TCP or UDP port number. PCM Pulse code modulation Process by which an analog signal is converted into digital information. PCR Peak cell rate As defined by the ATM Forum the parameter specifying in cells per second the maximum rate at which a source may transmit. PDN Public data network Generally for a fee a PDN offers the public access to a computer communication network operated by private concerns or government agencies. Small organizations can take advantage of PDNs aiding them to create WANs without investing in longdistance equipment and circuitry. PDU Protocol Data Unit The processes at each layer of the OSI model. PDUs at the Transport layer are called segments PDUs at the Network layer are called packets or datagrams and PDUs at the .
