Understanding the Time-to-Connect Metric
The “Time-to-Connect” QoE metric represents the sum of the times you need to pass each connection phases successfully.
There are four phases of connection: Association, Authorization, DHCP, and Portal Authorization. If the total time to connect takes longer than the selected threshold, the connection will be considered as a failure (failure to reach the goal). In this case, the phase that took longer than usual will be designated as the cause of the failure.
The threshold can be configured from 2s to 20s. The default threshold value is 2s.
The “Time-to-Connect” metric tracks failures in the following four phases:
Association - Once authentication is complete, clients can associate with an access point for full network access. Association allows the Access Point to register each client so that frames are delivered correctly.
Authorization - This phase refers to the phase in which the system uses the access control rules to decide whether access requests from (authenticated) consumers shall be approved (granted) or disapproved (rejected).
DHCP - The DHCP phase refers to the phase where clients obtain a DHCP lease for an IP address, a subnet mask, and various DHCP options from DHCP servers in a four-step process:
DHCP DISCOVER: The client broadcasts a request for a DHCP server.
DHCP OFFER: DHCP servers on the network offer an address to the client.
DHCP REQUEST: The client broadcasts a request to lease an address from one of the offering DHCP servers.
DHCP ACK: The DHCP server that the client responds to acknowledges the client, assigns it any configured DHCP options, and updates its DHCP database. The client then initializes and binds its TCP/IP protocol stack and can begin network communication.
Portal Authorization - The failure occurred during the Captive Portal Authorization phase.