Data Collection

Overview

This article explains how network performance data is collected, transported, and visualized in Cisco Crosswork Assurance. It clarifies key terminology, outlines data sources and flow, and summarizes SNMP trap versus polling.

Both Crosswork Assurance and non-Crosswork Assurance devices can collect key performance indicators (KPIs) that are sent to Crosswork Assurance.

Terminology Alignment

To align terms used across components:

Legacy Orchestrator (formerly Skylight Orchestrator)

• Network Element: Device that generates performance metrics.
• Collection Matrix: View showing the device session being polled for data.
• Statistics: Contain the key performance indicators (KPIs).

Cisco Crosswork Assurance (formerly Analytics)

• Monitor Session: Device generating performance metrics.
• Session: Device collecting metrics being polled for data.
• Performance Metrics: Contain the KPIs.

Data Sources

Legacy Orchestrator collects performance monitoring data from managed and non-managed devices. Performance monitoring data can originate from:

• Cisco® GT/GT-S, LT-S, and LX-S
• Cisco® Crosswork Assurance Sensor Control
• Cisco® Assurance SFP
• Cisco® Assurance Module
• Other vendor applications that reflect frames or packets.

For non-Crosswork Assurance devices, SNMP is used to discover devices and sessions. Rules based on discovery determine which sessions, devices, and interfaces are visualized.

Data Flow and Collection

• Legacy Orchestrator streams collected performance data from managed devices to Cisco Crosswork Assurance in CSV format.
  
• The Sensor Collector polls devices and sends resulting files to Cisco Crosswork Assurance.

Capture Data

Packet capture refers to the interception of a data packet at a specific network point for short-term storage and analysis, after which the packet can be downloaded, archived, or discarded.

Packet sniffers intercept and log network traffic via wired or wireless network interface on a host machine.

After capture, Cisco Crosswork Assurance analyzes the raw packet data and presents it in a readable format for visualization.

Session Examples (KPIs)

Here are some examples of data collected via Legacy Orchestrator from Cisco Crosswork Assurance devices:

TWAMP Session from Sensor Control

The information circled in this screen capture presents the actual values that will be streamed to Cisco Crosswork Assurance.

TWAMP Session from Cisco LT-S

The information underlined in this screen capture, presents the actual values that will be streamed to Cisco Crosswork Assurance.

The KPIs are outlined in red

CFM Sessions from Cisco LT-S

Cisco LT-S CFM sample session MEP statistics.

Cisco LT-S CFM sample session DMM statistics.

Cisco LT-S CFM sample Packet loss

PAA Session from Cisco LT-S

PAA offers the capability to measure QoS performance metrics at the IP and Ethernet layers.

The KPIs are the columns boxed in gold.

Legacy Orchestrator Configuration

To configure Legacy Orchestrator to stream CSV files to Cisco Crosswork Assurance:

1. Go to Collection > Server Configuration.
2. Use the following configuration:
   • Use Crosswork Assurance Legacy Orchestrator as default server for metrics collection: Check to export metrics from Cisco GT/GT-S, LT-S, and LX-S (PAA, BRW, SOAM, etc.) and Sensor Control (NFV SOAM, flowemeter, etc.)
   • Enable export of performance sessions: Check to export metrics from Legacy Orchestrator sessions.
   • User, Password, Host: Sensor Collector host OS IP address and credentials
   • Directory: Sensor Collector data directory
3. Click Test to test your connection with Sensor Collector.
4. Click Apply.

SNMP: Traps vs. Polling

SNMP follows the command center-agent model, where you have a central command center, and multiple agents at various remote locations. Agents collect operational information—including self-status such as system alarms—and report it to the command center. Communication mechanisms include SNMP traps and SNMP polling.

• Traps: Agents send immediate notifications to the command center when events occur. Limitation: If no trap is sent, the command center cannot confirm agent health.
• Polling: The command center regularly requests data from agents. If an agent is offline, no response is returned, indicating a potential issue.

Recommendation: Choose a hybrid approach—such as that supported by Cisco Crosswork Assurance—which uses both traps and polling to combine immediacy with ongoing health checks.