Hi everybody!
In this theme, I want to explain networking protection in upstream network – ethernet link aggregation.
Nowadays, customers want reliable services. They have little tolerance for service interruptions. Especially business users. Because of that, we must have protection in downstream, upstream protection and redundancy component in OLT.
Common GPON upstream networking protection modes are: ethernet link aggregation, ethernet port protection group and MSTP and ERPS.
Now, I will shortly explain an ethernet link aggregation. After that, I will show commands for configuration this protection.
Link aggregation group or shortly LAG is a logical link between two devices. Two or more physical links can aggregate in one logical link. Bandwith of a LAG is equal to the total bandwidths of all links in a LAG. Aggregation group allows higher bandwidth and reliability for ethernet links. Links in LAG can dynamically backup each other. When the system has a problem with one link, another link immediately takes its place.
There are two types of aggregation groups: manual and LACP (static and dynamic) aggregation. If devices are supported LACP, LACP is recommended. Because of that, I will shortly explain LACP aggregation.
LACP is an abbreviation of Link Aggregation Control Protocol. This is the control protocol for implementing link aggregation. Devices exchange aggregation information and agree with the aggregation information. Aggregation information are physical status, working mode, rate and LACP priority.
After established interconnection between 2 devices (2 to 4 uplinks exist between an OLT and the gateway), LACP sends packets in two modes:
Event-triggered: some event triggers that device sends packets, such as a change in local configuration or state of the local device.
Periodic: the system periodically sends packets (shot timeout: 0-10 s or long timeout: 20-40 s, a short time out is default). The target of this is to maintain the link between devices.
LACP support static and dynamic link aggregation mode.
Static link aggregation mode has a simple configuration and high reliability. Static link aggregation supports the load sharing mode and load-non sharing mode.
Dynamic link aggregation is very flexible and difficult to use. OLT does not support this mode.
1. Command for configuration LAG on the same upstream board 0/8, ports 0 and 1:
TEST(config)#link-aggregation 0/8 0-1 ingress workmode lacp-static
2. Command for configuration LAG on two upstream boards 0/8 port 0 and 0/9 port 0:
TEST(config)#link-aggregation 0/8 0 0/9 0 egress-ingress workmode lacp-static
3. Command for display link-aggregation:
TEST(config)#display link-aggregation all
Thank you!
