OSN3500 SSN1IDQ1 service board can access and process 4-channel STM-1 ATM services supporting standard optical interfaces of Ie-1, S-1.1, L-1.1, L-1.2 and Ve-1.2. With E1 service processing board N1PQ1/N1PQM, it can access and process IMA services.ATM switching capacity is 1.2Gbit/s in one direction and 600Mbit/s in both directions.Maximum uplink bandwidth is 8xVC-4 or 63xVC-12+7xVC-4, and it supports slot bandwidth self-adaptation. Supports up to 63 E1 IMA services. Supports mapping of up to 16 IMA groups to ATM ports, with each group supporting 1 to 32 E1s. Supports mapping of up to 16 non-IMA group E1 links to ATM ports.

Problem Description

When customers query the 5-minute performance of IDQ1 single board, they find that there is a loss of credits at a certain time of the day, as shown in the attached figure 2009-1-15 16:44:30~2009-1-16 12:34:30 There is a loss of 5-minute performance, host version V1R7, network management version V2R6C01B01SPC005.

Process

At present, there is no automatic reporting function for ATM performance, so if you want to save long-term continuous ATM performance data, you can only query it regularly before data bypass. If it is set to 5 minutes, it will be queried every 80 minutes, if it is set to 15 minutes performance, it will be queried every 4 hours; if it is set to 30 minutes, it will be queried every 8 hours; and

Root Cause

1. The processing of the network administrator's query for historical ATM performance

When the user clicks the query, the network manager will issue the command to query the historical ATM performance to the network element side, and save the data queried from the network element side into the database of the network manager. There is a range of historical data on the query interface of the network manager, and the network manager will find the data in this database whose time meets the conditions and display them. By default, the network manager will save up to 100,000 entries before dumping.

2. Device-side handling of ATM performance

On the device side, as long as the ATM performance monitoring is set to start and the port is allowed to monitor, the device will detect the ATM performance data and generate historical data when it reaches the end of the cycle, which is saved on the device side. Currently, the device has three types of cycles, 15-minute, indeterminate cycle (default is 5-minute), and 24-hour cycle, in which the 15-minute and indeterminate cycle performance can save up to 16 cycles of historical performance, and the 24-hour cycle can save up to 6 cycles of performance, and if the save is full, it will be saved by means of bypassing (i.e., deleting the oldest data), and the latest data will be saved in.

The ATM performance is designed with reference to the SDH performance completion. The SDH performance recommendations state that a maximum of 80 minutes of historical data can be saved for indeterminate cycles (5-minute cycles), and a maximum of 4 hours of historical data can be saved for 15 minutes.

Assuming that it is currently 12 o'clock, when you query the historical performance at this time, the historical performance obtained from the query will be placed on the network management side at this time. Then wait until 16:00 to query again, due to the indefinite cycle (5-minute cycle) can only save up to 16 cycles of 80 minutes, that is, at this time the query can only be saved from 14:40 to 16:00 historical data, at this time displayed on the network management, there will be 12:00 to 14:40 data does not exist, the customer mistakenly believe that the data is lost. So it is normal for customers to have performance counts lost at certain times of the day.

Suggestion and Summary

For non-automatically reported performance data, it can only be saved on the network management after active querying on the network management, and the historical performance saved on the device is valid for 16 cycles (15 minutes and variable cycles), that is, each query on the network management can only query the historical performance of the network element for the last 16 cycles, and if the interval between the two queries is more than the total time of the 16 cycles, it is equivalent to a part of the historical performance being missing on the network management, which is a normal phenomenon. If the time interval between two queries exceeds the total time of 16 cycles, the network administrator will lose part of the historical performance, which is a normal phenomenon.

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