EPON compatible with the current Ethernet technology for the purpose of the 802.3 protocol in the optical access network continuation of the full inheritance of the Ethernet low prices, flexible protocol, mature technology and other advantages, with a wide range of markets and good compatibility.
The GPON is positioned in the telecommunications industry for multi-service, full-service access with QoS guarantees, and strive to find the best and most business-friendly solution with the highest efficiency. It proposes that “all agreements be openly and completely thoroughly Reconsider “.
Overall, EPON and GPON have their own strengths and weaknesses, from the performance indicators GPON is better than EPON, but EPON has the advantage of time and cost, GPON is catching up, looking forward to the future of broadband access market who may not be replaced, it should be Co-existence and complementarity. GPON will be more suitable for customers with high bandwidth, multi-service, QoS and security requirements and ATM technology as the backbone. For cost-sensitive, QoS, security, less demanding customer base, EPON has become the dominant.
Broadband access Gigabit access era, 10G PON PON has become the mainstream technology, the traditional PON is to 10G PON upgrade, broadband will increase 10 times. 10G PON scale commercial launch, will directly help FTTH to Gigabit access rate evolution. The company is located in:
10G PON has many advantages, based on the existing hardware architecture to upgrade the network, greatly reducing costs, and shorten the transformation cycle, more crucially, PON upgrade to 10G PON, the bandwidth can be increased 10 times. Only through the upgrading of key components, you can enter the “Gigabit era” from the “Fast trillion times.”
Gigabit bandwidth is not the limit, with the rapid development of 8K ultra-high definition video and Internet of Things technology, especially the advent of the 5G era, will bring greater bandwidth demand for the network growth, in this context, 10G PON will continue Development, will be 100G PON evolution.
From the standard progress, 100G PON has been in IEEE / FSAN / ITU-T and other standardization organizations. IEEE set up the NG EPON research group, the standard named P802.3ca, mainly for 25G PON, 50G PON, 100G PON standardization is scheduled to be released in May 2019 standards; ITU-T also set up a 25G PON research group, Research on single wavelength rate improvement.
FTTB (Fiber To The Building): FTTX + LAN is a network connection mode, the optical signal is mainly connected to the office building or apartment building within the main distribution box to achieve optical fiber signal access, and in the office building or The interior of the apartment building is still the use of coaxial cable, twisted pair or fiber optic distribution signal to achieve the realization of high-speed data applications. We call FTTX + LAN broadband access network (referred to as FTTB), this is one of the most reasonable, most practical, most cost-effective broadband access methods.
Fast: Fiber to the floor, cable home, the user uplink and downlink rates generally up to 10Mbps-50Mbps, up to 100Mbps.
Large capacity: each household can enjoy the two-way balanced 10M-50Mbps bandwidth.
Investment Province: FTTB is mainly used for transformation of old residential areas. Residential areas that already have network cables, telephone lines and coaxial cables do not need to deploy optical fibers and save a large amount of wiring expenses.
Low price: Unit bandwidth is cheaper than FTTH and CMTS
Wide range of applications: High-speed Internet access, VOD, SOHO, distance education, video conferencing, ROBO, telemedicine and Internet connectivity.
The Address Resolution Protocol, or ARP(Address Resolution Protocol), is a TCP/IP Protocol that obtains physical addresses based on IP addresses.When sending information, the host will broadcast the ARP request containing the target IP address to all hosts on the local area network, and receive the return message to determine the physical address of the target;After receiving the return message, the IP address and physical address will be stored in the local ARP cache and reserved for a certain time. The next request will directly query the ARP cache to save resources.
OLT device is an important terminal device, which can be connected with the front-end switch by network wire and converted into optical signals.And like ONU device, it is a photoelectric integrated device.It has three functions:
Broadcast Ethernet data to ONU
Initiate and control the ranging process and record the ranging information
Allocate bandwidth for ONU;That is to control the start time of sending data by ONU andthe size of the sending window
For large-scale networks, our usual practice of IP planning is to divide VLANs, because dividing VLANs has many benefits, which facilitates management and improves the security of the entire network. Of course, in addition to dividing VLAN there are other methods? The answer is yes, that is port isolation. These two methods are the most used in ip planning. In this issue, we will learn more about VLAN division and port isolation.
When faced with many IP addresses, our common method is to divide VLANs. The role of VLANs is to isolate broadcasts. The same VLAN is in a broadcast domain. Port isolation is to isolate different ports of the same VLAN. Use a three-layer switch to divide vlans, so that vlans can communicate with each other.
The main advantages of VLAN :
Restrict the broadcast domain. The broadcast domain is restricted to one VLAN, which improves network processing capabilities.
Enhance the security of the local area network. The advantage of VLAN is that the broadcast and unicast traffic within the VLAN will not be forwarded to other VLANs, which helps to control network traffic, reduce equipment investment, simplify network management, and improve network security.
Flexible construction of virtual working groups. VLANs can be used to divide different users into different working groups, and users in the same working group do not have to be limited to a certain fixed physical range, and network construction and maintenance are more convenient and flexible.
As we mentioned above, VLAN is a good solution for networks. In addition to VLAN, port isolation can also be used. Users can add different ports to different VLANs, but this will waste limited VLAN resources. The port isolation function can be used to achieve isolation between ports in the same VLAN. The user only needs to add the port to the isolation group to realize the isolation of the Layer 2 data between the ports in the isolation group. Port isolation is generally used in the intranet.Isolated ports can not communicate with each other,so it provides the user a safer solution of network.
In short：The role of VLAN is to isolate broadcasts. The same VLAN is in a broadcast domain. Port isolation is to isolate different ports in the same VLAN.
Access Port vs Trunk Port vs Hybrid Port
We know that different network segments need to be forwarded through routing to communicate.PCs between different VLANs on the same network segment cannot communicate with each other. In fact, this is not absolute. After understanding the various labels of VLAN, we can realize the data intercommunication of different network segments without routing.
The switch port has three working modes, named Access, Hybrid, and Trunk.
Access type ports can only belong to one VLAN, and are generally used to connect to a computer port.
Trunk type ports can allow multiple VLANs to pass, and can receive and send packets of multiple VLANs. They are generally used for ports connected between switches.
Hybrid type ports can allow multiple VLANs to pass through, can receive and send packets from multiple VLANs, and can be used to connect between switches or to connect to a user’s computer.
When the Hybrid port and Trunk port receive data, the processing method is the same. The only difference is when sending data: Hybrid port can allow multiple VLANs packets to be sent without tag, while Trunk port only allows default tagged VLAN message to be sent without tag.
C-DATA ONU IP address default is 192.168.101.1
Yes, C-Data Wireless Ap Ceiling type CW8837AP and outdoor type CW9833AP both meet 802.11ac standard.
A wireless AP (AP, Access Point, Wireless Access Point, Conversation Point, or Access Bridge) is a well-known name that includes not only simple wireless access points (wireless APs), but also wireless routers Gateway, wireless bridge) and other types of equipment collectively. It mainly provides wireless workstations for wired LAN and wired LAN access to wireless workstations, wireless access point within the coverage of wireless workstations can communicate with each other.
Simple wireless AP is a wireless switch that provides wireless signal transmission and reception functions. Simple wireless AP’s working principle is the network signal transmitted over twisted pair, after AP product compilation, the electrical signal is converted into a wireless signal sent out to form a wireless network coverage. According to different power, it can achieve different degrees and different ranges of network coverage, the maximum wireless AP coverage of up to 500 meters. Most simple wireless AP itself does not have the routing function, including DNS, DHCP, Firewall, server functions must have independent routing or computer to complete.
Ethernet Over Coax also called EOC for short. It is an equipment which used for triple play service in a new generation broadcasting network. Widely used by consumers and telecommunications operators in existing 75 ohm coaxial cable installations (from cable television or CATV), to carry broadband data into and through the home, and into multiple dwelling unit (MDU) installations.
Data EOC network is built with EOC Master and EOC Slave.
Hybrid fiber-coaxial (HFC) is a telecommunications industry term for a broadband network that combines optical fiber and coaxial cable.
In a hybrid fiber-coaxial cable system, the television channels are sent from the cable system’s distribution facility, the headend, to local communities through optical fiber trunk lines. At the local community, a box called an optical node translates the signal from a light beam to electrical signal, and sends it over coaxial cable lines for distribution to subscriber residences. The fiberoptic trunk lines provide adequate bandwidth to allow future expansion and new bandwidth-intensive services.
ONU consists of active Optical Network Unit and passive Optical Network Unit.It has two functions: selective reception of the broadcast sent by OLT, and receiving response to OLT if the data is needed;The Ethernet data that the user needs to send is collected and cached, and the cached data is sent to the OLT side according to the assigned send window.
Switches, routers are almost all network devices used in modern local area networks. Among them, switches are responsible for connecting network devices (such as switches, routers, firewalls, wireless APs, etc.) and terminal devices (such as computers, servers, cameras, network printers, etc.) ); The router realizes the interconnection between the local area network and the local area network, and the interconnection between the local area network and the Internet; In general, the switch is responsible for connecting devices, the router is responsible for connecting to the network.
The function of the switch is to connect terminal devices such as computers, servers, network printers, network cameras, IP phones, and realize the interconnection with other network devices such as switches, wireless access points, routers, network firewalls, etc., so as to build a local area network and realize all devices Communication between.
The switch is located in the second layer (data link layer) of the OSI reference model. The work of the switch relies on the identification of the MAC address (all network devices have a unique MAC address, which is usually directly burned into the network card by the manufacturer) ).
Routers are also called gateways, which connect local area networks to form a larger wide area network. When connecting heterogeneous networks (heterogeneous networks refer to different network types, such as ATM networks, FDDI networks, Ethernet networks, etc.). Heterogeneous networks use different data encapsulation methods and cannot communicate directly, and routers can “translate” these different encapsulated data to achieve communication in heterogeneous networks. In addition, for the local area network, the wide area network is undoubtedly a heterogeneous network.
In general, the main differences between routers and switches are reflected in the following aspects:
(1) Different levels of work
The original switch worked at the data link layer of the OSI/RM open architecture, which is the second layer, and the router was designed to work at the network layer of the OSI model from the beginning. Since the switch works on the second layer of OSI (data link layer), its working principle is relatively simple, while the router works on the third layer of OSI (network layer), it can get more protocol information, and the router can make Smarter forwarding decisions.
(2) The data forwarding is based on different objects
The switch uses the physical address or MAC address to determine the destination address of the forwarded data. The router uses the ID numbers (ie IP addresses) of different networks to determine the address for data forwarding.
(3) Traditional switches can only divide conflict domains, not broadcast domains; routers can divide broadcast domains
The network segment connected by the switch still belongs to the same broadcast domain. Broadcast data packets will spread to all network segments connected to the switch, and in some cases will cause communication congestion and security vulnerabilities. Although the switches above the third layer have the VLAN function, they can also be divided into broadcast domains, but the sub-broadcast domains cannot communicate, and the communication between them still requires a router.
(4) The router provides firewall services
The router only forwards data packets with specific addresses, and does not transmit data packets that do not support routing protocols and network data packets whose purpose is unknown, which can prevent broadcast storms. Switches are usually used for LAN-WAN connections. Switches are classified as bridges, which are devices at the data link layer. Some switches can also achieve Layer 3 switching. In contrast, routers are more powerful than switches, but they are relatively slow and expensive. The three-layer switch combines the wire-speed packet forwarding capability of the switch and the good control function of the router, so it is widely used.
Whether it is a switch, a router , the realization of the functions of these network devices requires the network engineer to configure the device in advance (such as VLAN virtual network port division, firewall security policy configuration, router default gateway setting, etc.). At a different level, these network devices are computers with cpu and memory, and all implement hardware functions through the “translation” of the cpu to the machine language.
Switches are the common equipment for data forwarding in local area networks(LAN), and their performance and functions determine the manageability and data forwarding performance of the LAN. The following aspects should be considered when choosing a switch:
Number of ports
The number of physical ports supported by the switch determines the number of terminals or secondary devices connected to the switch, which need to be selected according to actual needs. Of course, subsequent network expansion needs to be considered. The access port of the switch is used to connect the internal network terminal, and the uplink port is used to connect to the upper-level equipment.
2.Port Speeds and Types
Switches come in Fast Ethernet and Gigabit Ethernet. Fast Ethernet allows up to 100 Mb/s of traffic per switch port while Gigabit Ethernet allows up to 1000 Mb/s of traffic per switch port. These ports may be a combination of SFP/SFP+ slots for fiber connectivity, but more commonly they are copper ports with RJ-45 connectors on the front, allowing for distances up to 100 meters. With Fiber SFP modules, you can go distances up to 40 kilometers. Currently, Gigabit Ethernet is the most popular interface speed though Fast Ethernet is still widely used, especially in price-sensitive environments.
3.Switch access capacity
The amount of equipment attached to the switch is mainly reflected in the depth of the MAC address table of the switch. At the same time, it is also necessary to pay attention to the number of host routing entries for the three-layer switch. For example, when selecting a Layer 3 switch, the number of all access terminals of the Layer 3 switch is required to be less than the number of host routing entries of the Layer 3 switch.
4.Network scale and switch network structure
Considering the scale and level of switch application networks, which are mainly divided into small and medium-sized networks and large and medium-sized networks, the recommendations are as below:
Divide VLANs to realize that ports belonging to different VLANs can’t communicate with each other; Set static routes to realize that VLANs of different network segments can communicate with each other; DHCP snooping prevents the access of other DHCP servers from affecting the LAN. The above functions are commonly used in large and medium LANs.
Specifically, such as: Access Control List, 802.1X authentication(Radius,Tacacs+), loopback detection, IGMP Snooping, etc.
At any layer, a modern switch may implement power over Ethernet (PoE), which avoids the need for attached devices, such as a VoIP phone or wireless access point, to have a separate power supply. Since switches can have redundant power circuits connected to uninterruptible power supplies, the connected device can continue operating even when regular office power fails. Another characteristic you consider when choosing a switch is PoE. This is the ability of the switch to deliver power to a device over the existing Ethernet cabling. To find the switch that is right for you, all you need to do is choose a switch according to your power needs. When connecting to desktops which do not require PoE switches, the non-PoE switches are a more cost-effective option.