A queuing delay is a wait while a router prepares and transmits packets. Routers with multiple packets to handle set up a queue for processing, because they can only deal with one at a time. This creates a delay until the router can clear data and start transmitting in real time. The length of the delay depends on several factors. In network troubleshooting, technicians may check for queuing delay and similar issues to explain dropped packets, slow connections, and other complaints.
When a user sends a single packet to a waiting router, the device can immediately process and send out the information. With a burst transmission, a user sends several packets at once. Routers can also be deluged in information from multiple users all attempting to send packets at the same time. This forces the router to assign priorities and create a queue since it can't process them simultaneously. Packets wait until the router has time to process and dispatch them, and they are usually handled in order of arrival.
The queuing delay can be very short when a router has a limited number of packets waiting to be sent. In this case, users might not initially notice a lag. When packets start to stack up, however, the delay can grow lengthy, The router may also start to drop packets. It runs out of room to store the information waiting for processing, and must jettison some of the packets to stay functional, which relates in data loss. This can create issues like burst errors, where a large data transmission fails because the router doesn't have enough of a buffer.
Small buffers allow for only a limited number of packets in the queue before the router begins to drop data. Larger buffers create more room for storage, but also demand more resources. Designers have to think about the needs of a network and the demands that may be placed on a router when they develop equipment. These considerations are also important for router and network configuration. Changes to the settings can sometimes address lag and problems like queuing delay, if the router has the capability to implement the changes.
Network congestion can be a significant problem on a busy network. Users in an office setting typically expect quick responses, but at the same time, they can place a high load on the router. This can create a significant queuing delay as the router struggles to keep up. Technicians work to avoid burst errors and dropped packets by configuring the equipment and making sure the attached cable to connect to external networks is free of defects.
