Basic Knowledge of OLT Equipment
With the rapid development of communication technology and the promotion of "Broadband China Optical Network City" strategy, the cable broadband service has extended from cities and towns to the vast rural areas, and the market competition is increasingly fierce. In order to meet the needs of users for high-speed broadband, broadband speed-up has become the primary problem faced by major operators. Based on many years of experience in the industry of Sushan Weida, this paper mainly introduces the basic knowledge of OLT equipment and its planning and deployment ideas, hoping to help practitioners.
I. What is OLT Equipment
OLT (Optical Cable Terminal Equipment) in PON Passive Optical Network System (PON) is the terminal equipment connecting optical fiber transmission channel ODN, which provides the interface between PON system and service providers for core data, video and telephone network. OLT is not only a switch or router, but also a platform to provide multiple services. It provides an optical fiber interface for passive optical network. In addition to providing network centralization and access functions, OLT can also allocate bandwidth, network security and management configuration according to the different requirements of user's quality of service (quality of service, throughput, delay, jitter, loss rate, etc.). It is the core component of the whole PON system. Through OLT, all kinds of services are transmitted from one optical fiber to the user's proximal end. After optical branching through the optical splitter, the branch optical fiber is connected to the user end. It can not only monitor and manage equipment and ports, but also carry out business opening and user status monitoring. It also supports 1000Base-PX10/PX20 optical module, supports maximum spectral ratio of 1:64, and supports transmission distance of up to 20km.
Common OLT devices
ZTE OLT equipment. ZXA10 C200 has six slots, and a single frame can insert up to five PON boards, each PON board provides four PON ports; ZXA10 C220 has 10 slots, and a single frame can insert up to 10 PON boards, providing 40 EPON ports. ZXA10 C300 can support up to 128 PON ports.
2. Huawei OLT equipment. Huawei OLT equipment is mostly box structure, in which small specification MA5606T provides maximum 8 PON interfaces; medium specification MA5683T has 6 slots, maximum 8 PON interfaces, maximum support 768 users when full frame. Large capacity MA5680T has 20 slots, which can accommodate the maximum number of users 4K.
3. Bell OLT equipment. Large capacity 7342 ISAM FTTU is a high-end EPON OLT device with the highest switching capacity and the highest veneer density. Each veneer can provide 8 EPON ports, one subframe supports 14 slots, and a total of 112 EPON user interfaces. It can provide up-and-down symmetrical 1.25G/bps transmission rate, support 1:64 spectral ratio, and can cover users in the range of 60km.
4. Ericsson OLT equipment. The rack BM1500 is an OLT device with GPON access technology. It supports 320GBPS mass switching capacity, 16 slots, 64 GPON ports, 1:64 spectral ratio and dual standby power supply.
5. POWER OLT EQUIPMENT. AN5516-01 has 4 10GE or 12 GE interconnects, and the single board supports 4 1.25G EPON or 4 2.5G GPON or 1 10G EPON interfaces. AN5516-02 is a new generation of OLT equipment with large capacity. As a Gigabit IP switching platform, it has 48G core and 96G backplane switching capacity. The single frame has a maximum capacity of 4096 lines at 1:32 spectral ratio. It covers up to 20 km and has a transmission capacity of 10 KM km at 1:64 spectral ratio.