Support Support Downloads Knowledge Base Juniper Support Portal Community

Knowledge Base

Search our Knowledge Base sites to find answers to your questions.

Ask All Knowledge Base Sites All Knowledge Base Sites JunosE Defect (KA)Knowledge BaseSecurity AdvisoriesTechnical BulletinsTechnotes Sign in to display secure content and recently viewed articles

[EOL/EOE] Calculating rfping output on WLC controllers



Article ID: KB32514 KB Last Updated: 04 Dec 2020Version: 2.0

This article explains how to calculate round trip time (RTT) by using the rfping output in WLC, which can be used to diagnose any network connection issues.

Note: The products listed in this article has either reached hardware End of Life (EOL) and End of Engineering (EOE)



RTT and rfping can be used to troubleshoot the following symptoms:

  • Intermittent wireless connection
  • Latency in the wireless network

  • Slow wireless connection



Packet round trip time (RTT) is calculated in the following way:

  • For the first packet, the round trip time is the time of ACK reception minus the time that the packet was enqueued.
  • For the second and subsequent packets, RTT is the time of ACK reception of the current frame minus the time of ACK reception for the previous frame.
  • Because all the packets are enqueued at the same time, it is not possible to compute RTT from the packet-enqueue time for any packets other than the first packet.

For example:

WLC2800# rfping mac 64:27:37:aa:94:21

RF-Link Test to 64:27:37:aa:94:21
Session-Id: 119
Packets Sent  Packets Rcvd    RSSI     SNR    RTT (micro-secs)
------------  ------------   -------  -----  ----------------
          20            20      -42     52        241         


From the above “rfping” output:

  • Note that 20 ping packets were sent.
  • Now check whether 20 acknowledgement (ACK) receptions were received for these packets.
RTT is calculated based on the reception time of ACK of the ping packets. The overall average RTT of these 20 ping packets is shown in the rfping command output in WLC.


Modification History:
2020-11-30: Tagged article for EOL/EOE.
Comment on this article > Affected Products Browse the Knowledge Base for more articles related to these product categories. Select a category to begin.

Getting Up and Running with Junos

Getting Up and Running with Junos Security Alerts and Vulnerabilities Product Alerts and Software Release Notices Problem Report (PR) Search Tool EOL Notices and Bulletins JTAC User Guide Customer Care User Guide Pathfinder SRX High Availability Configurator SRX VPN Configurator Training Courses and Videos End User Licence Agreement Global Search