tcp ip from a security viewpoint

... exchanged route data and supports a hierarchical management of domains called Domain Confederations Case Study: Where Is the Data Coming From? 75 Until you actually take a look at a protocol analyzer, ... example, places its data structures (called packets) in the data portion of the Ethernet frame TCP (a layer above IP) places the communications streams it manages in the data portions of IP packets ... how data can make its way from a computer on one LAN to another computer on a totally different LAN that could be as far away as half−way around the world or out of this world entirely TCP/ IP does...

Ngày tải lên: 29/09/2013, 13:20

... mail service, on the other hand, is a large, complex piece of software that accepts data (mail) from and returns data to the client, as well as reads and stores data and configuration information ... that allowed an organization (or a person) to request an Internet address from a central authority and then expand on that name using their own authority Thus was born the Internet Domain Name ... Registration system Human−readable Internet addresses, like IP addresses, contain dots But Internet addresses can have as few as one dot or many more than four (although it is a rare address that...

Ngày tải lên: 29/09/2013, 13:20

... information or explanation on optimizing IP performance IP Stack IP Stack Delay and Latency IP MTU Data Data Data Data IP TCP Data Link Link Link IP TCP Data Link Header Trailer Trailer Header ... select an IP address automatically when DHCP is not available Note The APIPA address is selected from the IANA-reserved address block 169.254.0.0/16 APIPA does not provide a default gateway IP address ... Stack TCP/ IP Stack Host B Authentication and Encryption Policy SA Negotiations Internet Key Exchange SA SA TCP/ IP Stack TCP/ IP Stack Encrypted IP Packets IPSec Policies Routing IPSec Traffic Data...

Ngày tải lên: 21/12/2013, 05:18

Ngày tải lên: 31/03/2014, 16:26

... Managing Information Base HTTP Trial File Transfer Protocol TFTP Trivial File Transfer Program TCP Transmission Control Protocol UDP User Datagram Protocol IANA Internet Assigned Number Authority ... đề TCP UDP Tiêu đề ch a đ a IP đích đ a IP nguồn 32-bit chuẩn IPv4 Chúng thường xuyên mã h a đ a IP cấu hình giao thức bốn số thập phân tách rời dấu chấm D a vào trước, có ba đ a sử dụng danh ... đ a Có ba loại NAT mà thiết bị thuê.Các loại phương pháp biên dịch đ a gồm NAT tĩnh, pooled NAT mức cổng NAT với trễ d a vào biên dịch đ a cổng PAT(Port Address Translate) NAT tĩnh NAT tĩnh dẫn...

Ngày tải lên: 25/04/2013, 19:06

... wrong at this layer, at most, the IP layer will encapsulate part of the message in an ICMP packet and return it TCP Header - SYN Flag Frame Header Data Data IP Datagram Header Data TCP Header ... packet .ip. ihl=5; packet .ip. tos=0; packet .ip. tot_len=htons(40); packet .ip. id=getpid(); packet .ip. frag_off=0; packet .ip. ttl=255; packet .ip. protocol=IPPROTO _TCP; packet .ip. check=0; packet .ip. saddr=sadd; ... MAC SOURCE IP TARGET MAC TARGET MAC TARGET IP TARGET IP There is a protocol to match a MAC address to an IP address IDIC - SANS GIAC LevelTwo ©2000, 2001 17 As we consider how we will employ a...

Ngày tải lên: 26/10/2013, 23:15

... the application layer: System stack System stack Recovery of user's data Decapsulation Build up of Frame Encapsulation User's data User's data AH Application PDU Application Application AH PH AH ... CSUs contain additional facilities that are used to detect and isolate line and equipment problems 2.2 Making a Data Call Consider a host (Host A) in a multilocation company that needs a data file ... users’ data emerges at the application layer of Stack 2.3.1.2 Encapsulation and Decapsulation In descending the protocol stack, the overhead data added at each layer is placed in a header, or,...

Ngày tải lên: 27/06/2014, 00:20

... medium are accommodated, and a header and trailer are constructed Added to the IP datagram, they form the IP frame • In the physical sublayer the logical data stream is converted to a signal stream ... mediated analog telephone lines), so that a flag character or an escape character within the IP datagram payload shall not interrupt transmission, PPP employs character stuffing to change the meaning ... a Token Ring data frame The address fields contain the unicast hardware addresses of the destination and source or multicast or broadcast addresses • IEEE 802.2 LLC header: For IP datagrams and...

Ngày tải lên: 14/08/2014, 13:20

... Table 5.1 Comparison of Frames on Different LANs Field Size Ethernet IEEE 802.3 Preamble Variable 0×AA-AA -A 0×AA-AA-AA-AAA-AA-AA -A AA-AA-AA-AA A- AA-AB MAC Header Starting delimiter byte No 0×AB ... AAL Segmentation and layer AAL reassembly sublayer 48 byte cells ATM layer 53 byte cells Physical layer ATM adaptation layer parameters AAL type Bit rate Constant Connection mode CO 3/4 Variable ... class of traffic Figure 4.8 includes a table that summarizes their traffic handling ability 72 Wide Area Networks ATM network interface layer IP datagram ATM AAL Convergence sublayer adaptation...

Ngày tải lên: 14/08/2014, 13:20

... header Adding an IPsec encapsulating security payload header and trailer and an IPsec authentication trailer provides message integrity and authentication Finally, an IP header is attached that ... Encapsulating header Authentication header Original datagram D(1) IPSec encapsulating security payload tunneling datagram D(2) Encapsulating header Figure 6.7 ESP header Original datagram D(1) IPsec ... Together Hdr Payload Payload Label -VPI/VCI ATM cells Label -VPI/VCI Frame relay frames Payload Etc Hdr Payload Label-DLCI PPP frame Payload PPP header Payload Label-DLCI IP datagram PPP trailer MPLS...

Ngày tải lên: 14/08/2014, 13:20

... 23 data bytes 23 data bytes 23 data bytes 23 data bytes 23 data bytes 23 data bytes 23 data bytes 23 data bytes 23 data bytes 23 data bytes 23 data bytes 23 data bytes 23 data bytes 23 data bytes ... demands for data communication, and the perfection of digital voice, it became apparent to many PSTN operators that an all-digital network could carry both voice and data traffic Called integrated ... twisted pairs are called cable pairs A paired cable is a cable whose conductors are twisted pairs Commonly, twisted pairs are deployed in 25- or 50-pair bundles wrapped in a metal sheath known as a...

Ngày tải lên: 14/08/2014, 13:20

... network A. 3.1 Asynchronous Operation An asynchronous operation is an operation in which characters are framed by start and stop bits and sent as they are generated A straightforward example of asynchronous ... Class NAP (IN) TDM signal associated common channel signaling IN CO class NAP (IN) Local Loop ASP Local loop Users Analog signal associated in-band signaling (DTMF) IN Toll/tandem Toll/tandem ASP ... spectrum into separate, nonoverlapping frequency bands, a voice channel and upstream and downstream data channels are created This eliminates self-crosstalk as an impairment • Echo cancellation (EC):...

Ngày tải lên: 14/08/2014, 13:20

... Ethernet Frame HEADER PREAMBLE (8 bytes): 0×AA-AA-AA-AA-AA-AA-AA-AB (6 bytes): If address is unicast, contains the hardware address of a specific station If address is multicast, carries a code that ... First bytes may be used for AAL control information AAL5 Frame Containing IP Datagram LLC HEADER: standard SNAP HEADER: standard PAYLOAD B.3 Chapter 4: Wide Area Networks IP DATAGRAM (38 PAD 191 to ... IEEE 802.3 MAC HEADER PREAMBLE (7 bytes): 0×AA-AA-AA-AA-AA-AA-AA START DELIMITER (1 byte): 0AB (2 or bytes): If address is unicast, contains the hardware address of a specific station If address...

Ngày tải lên: 14/08/2014, 13:20

... the data link layer, a header and trailer, are attached by each layer to form a frame The procedure is known as encapsulation, and the headers and trailer are said to encapsulate the user data See ... the payload, to prevent misinterpretation of text, addition of a specific character ahead of a text character that mimics a command For an IP datagram on an asynchronous link, a character that ... header and the transport layer header in the IP datagram In IPv6, the IP datagram consists of a base header, extension headers, transport layer header, and message The authentication header is...

Ngày tải lên: 14/08/2014, 13:20

... ending of each IP datagram Server A device that stores data, organizes and maintains databases, and delivers copies of data files to clients on demand A process that stores and distributes data Service ... Wide-Area Data Network Performance Engineering, Robert G Cole and Ravi Ramaswamy Winning Telco Customers Using Marketing Databases, Rob Mattison WLANs and WPANs towards 4G Wireless, Ramjee Prasad ... using IP unicast addresses In addition, UDP is used whenever data is sent to multiple locations using IP multicast or broadcast addresses UDP data unit Application PDU encapsulated by a UDP header...

Ngày tải lên: 14/08/2014, 13:20

... for access to the transport medium are accommodated, and a header and trailer are constructed Added to the IP datagram, they form the IP frame • In the physical sublayer the logical data stream ... mediated analog telephone lines), so that a flag character or an escape character within the IP datagram payload shall not interrupt transmission, PPP employs character stuffing to change the meaning ... a Token Ring data frame The address fields contain the unicast hardware addresses of the destination and source or multicast or broadcast addresses • IEEE 802.2 LLC header: For IP datagrams and...

Ngày tải lên: 14/08/2014, 13:20

... Table 5.1 Field Preamble Comparison of Frames on Different LANs Size Ethernet IEEE 802.3 Variable 0×AA-AA -A 0×AA-AA-AA-AAA-AA-AA -A AA-AA-AA-AA A- AA-AB MAC Header Starting delimiter byte No 0×AB ... sublayer adaptation AAL Segmentation and layer AAL reassembly sublayer 48 byte cells ATM layer 53 byte cells Physical layer ATM adaptation layer parameters AAL type Bit rate Constant Connection ... that may be separated in time • AAL5 was created by an industry forum to send frame relay and IP traffic over an ATM network AAL5 supports connection-oriented, variable-bit-rate, and bursty data...

Ngày tải lên: 14/08/2014, 13:20

... datagram D(2) Encapsulating header Authentication header Original datagram D(1) IPSec encapsulating security payload tunneling datagram D(2) Encapsulating header Figure 6.7 ESP header Original datagram ... datagram with a UDP header and an L2TP header Adding an IPsec encapsulating security payload header and trailer and an IPsec authentication trailer provides message integrity and authentication ... from D(1), it is encrypted, and wrapped (encapsulated) in a second IP datagram I will call this datagram D[D(1)]2 to symbolize an encrypted IP datagram [D(1)] encapsulated by a second datagram...

Ngày tải lên: 14/08/2014, 13:20