hdlc

GPRS logic channel, namely public control channel, packet service channel and GPRS broadcast channel. The public control channel is used to transmit the control signaling of data communication, which is divided into paging and answering channels. Packet traffic channels are used to transfer grouped data. The broadcast channel is used to send network information to the mobile terminal. The LLC layer is the logical link control layer. It is a wireless Link protocol based on high speed data link

adjacent interfaces. For example, in Figure 2, node 200 should know his node/port pair (200, 3 is connected to node 2112 of node/port pair (2112, 1), similar, (200, 4) connected to (2112, 5), (200, 62) connected to (1701, 3). Figure 3 SONET/WDM Neighbor Discovery Sample Here are a few ways to discover your neighbors. (1) Discovery of the same layer When a neighboring device shares the common level of a reusable structure, such as a SONET access multiplexer connected to the SONET path switch

mode of F0/3 (Config) # interface range fa 0/1-2 enter the port configuration mode from F01 to F0/2 (Config-if) # Set speed 10 to 10 M. Optional values: 10,100 and auto. (Config-if) # The duplex full Configuration Port is in full duplex mode. Optional values: full (full duplex), half (semi-dual), and auto (Adaptive) (Config-if) # no shutdown to enable this port (Config) # interface serial 1/2 enters the configuration mode of port S1/2 (Config-if) # ip address 1.1.1.1 255.255.255.0 c

layer can only use the PPP protocol, rather than non-standard HDLC protocol. The implementations of the latter are inconsistent with those of different vendors; 3. The network layer routing configuration adopts mainstream routing protocols, such as OSPF. Use the default configuration options whenever possible. Special optimization is not recommended in the environment where devices of multiple vendors are interconnected; 4. The unified network manage

) # framing sf/esf | crc4/nocrc4 (sf/esf-Router (config-controller) # T1, crc4/nocrc4-E1) Router (config-controller) # linecode ami/b8zs/hdb3 (ami-T1, hdb3_e1) Router (config-controller) # cablelength short 133/266 (optional, used if the cable length is less than 655 feet) Router (config-controller) # cablelengh long gain26/-15 (optional, if the cable length is greater than 655 feet, the value is DB gain) Router (config-controller) # line termination 75-ohm | 120-ohm (optional, meaning obvious)

For vrouters of different manufacturers, because of their different implementation methods, there is a certain degree of configuration. Take the vrouters of Cisco and Intel as an example. DDN connection (Static) Intel 9100 settings: Basic WAN1: Leased Line PPP WAN2: Unused Next Bandrate (bps): 64 K based on the user's actual situation Link Name: Test-Link1 user defined Next IP Routing: RIP-1 IPX Routing: Disabled WAN Bridging: Disabled Next IP Address: 10.1.0.1 NetworkMask: 255.255.255.0 Protoco

: SDLC, HDLC, PPP, STP, Frame Relay, and so on. 3. Network Layer Network layer is responsible for routing the packets between subnets.　　　　In addition, the network layer can also realize congestion control, Internet interconnection and other functions.　　　　At this level, the unit of data is called a packet (packet).　　　　Network layer protocol representatives include: IP, IPX, RIP, OSPF, and so on. 4, the Transport layer (Transport layer) Transport layer

-sending, etc. In this layer, the units of the data are called frames. The Data Link layer protocol includes: SDLC, HDLC, PPP, STP, Frame Relay, and so on.Implementation, Linux provides a Network device abstraction layer, in fact, now LINUX/NET/CORE/DEV.C. Specific physical network devices in the device driver (DRIVER.C) need to implement the virtual function. The network device abstraction layer invokes the functions of the specific networking device

address. In the above procedure, you can see that there is a routing table query process, and the establishment of this routing table depends on the routing algorithm. That is, the routing algorithm is actually used only to update the maintenance routing table between routers, the real data transfer process does not execute this algorithm, only view the routing table. This concept is also important and requires understanding of commonly used routing algorithms. And the whole TCP protocol is mor

, BSC6000Equipment,. 3221229568.3221231044.3221291023.3231693419, Bsc6000Equipment, 18, MOIndex, className, fdn, name, neID, 18, BSC6000Function,. 3221229568.3221231044.3221291023.3231697515, Bsc6000Function, 18, BSCIndex, GrpIndex, MOIndex, className, fdn, name, neID, 0, 0, 18_0_0, BSC6000HDLCLinkGrp,. 3221229568.3221231044.3221291023.3221721098, HDLC link set, 18, Note: There are many similar rows and columns in this txt file. The rule is that

its widespread adoption. Working principle of OSPF Dynamic Routing Protocol As mentioned above, the OSPF dynamic routing protocol is a link-state dynamic routing protocol. How does OSPF describe the link connection status? The abstract model Model1 indicates that an Ethernet interface of a router is connected to only one Ethernet segment instead of other routers. In this case, router R1 running OSPF can only identify itself and cannot identify the devices (hosts, etc.) on this network segment )

Advanced Layer 2nd features: PPP/MLPPP, FR/MFR and HDLC, IEEE 802.1Q, and 802.1D bridging.Standard-based Advanced Layer 3rd features: OSPF, RIP, r00002, BGP4, and VRRP. Rich service quality features enable convergence of advanced services and multimedia: 8 priorities, classification-based priority and traffic management, configurable bandwidth conventions, Diffserv and ToS; random Early Detection packet discarding for TCP data streams. Advanced Secur

1. CDP is a Cisco proprietary protocol and can only find information about directly connected devices.2. Cisco routers send CDP updates on all interfaces by default. The default Update time is 60 s and the retention time is 180 s.3. CDP messages are encapsulated in the header and tail of the data link layer. Without any layer-3 protocol, the data link layer must support the subnet Access Protocol (SNAP) header. Currently, most protocols support SNAP, such as Ethernet,

-Protocol router (multiprotocol router) IP (Internet Protocol): network Protocol (forwarding groups between heterogeneous networks) ARP (Address Resolution Protocol): Address Resolution Protocol RARP (Reverse Address Resolution Protocol): Reverse Address Resolution Protocol ICMP (Internet Control Message Protocol): Internet Control Message Protocol IGMP (Internet Group Manage Protocol ): Internet Group Management Protocol BOOTP (Bootstrap): optional security start Protocol Data Link: bridge swit

2 m leased line configured into the frame mode non-frame mode VWIC2-2MFT-T1/E1 can be configured into the frame mode of 2 m leased line, and voice 30B + D line. You cannot configure it to a non-frame mode. The configuration is as follows: card type e1 0 0 controller E1 0/1/0 framing NO-CRC4 channel-group 0 timeslots 1-31 interface Serial0/1/0 ip address 192.168.1.1 255.255.255.255.252 voice 30B + D line: card type e1 0 0 isdn switch-type primary-net5voice-card 0 controller E1 0/0/0 framing NO-C

transmission, and each circuit on the action series. The data link layer provides reliable transmission on unreliable physical media. The role of this layer includes physical address addressing, data frame formation, traffic control, data error detection, and re-transmission. At this layer, the unit of data is frame ). Data link layer protocols include SDLC, HDLC, PPP, STP, and frame relay. The main function of the link layer: the link layer provides