Voip call setup delay

In the presence of high levels of delay the normal "protocol" of conversation breaks down. In addition, delay can make echo problems more obvious and annoying. Enable timestamping by adding the commands: service timestamps debug datetime msec , service timestamps log datetime msec in enable mode. The timestamps help determine the interval of time between state changes.

This document is intended for the networking personnel involved in the design and deployment of VoIP networks. Readers of this document should be knowledgeable of these topics:.

This document is not restricted to specific software and hardware versions. The information presented in this document was created from devices in a specific lab environment.

All of the devices used in this document started with a cleared default configuration. If you are working in a live network, ensure that you understand the potential impact of any command before using it. For more information on document conventions, refer to the Cisco Technical Tips Conventions. An important factor to consider before you start any VoIP troubleshooting or debugging is that VoIP calls are made up of three call legs.

This is shown in this diagram. Troubleshooting and debugging needs to first focus on each leg independently and then on the VoIP call as a whole. These definitions explain the function of the main components displayed in the router call flow diagram:. This diagram shows the architecture of Cisco router Telephony building blocks and how they interact with each other.

Call Peer —The Call Peer is the opposite call leg. It shows if the digital T1 connection between the router and switch CO or PBX is up or down and if it functions properly.

The output of this command looks like this:. If using E1 use the show controllers e1 command. For more information, refer to:. T1 Layer 1 Troubleshooting. AleDema Probably not, it would use higher level libraries instead. ImagicTheCat I meant the in game implementation of Mumble. It seems like its slowly becoming the standard. Skip to content. Star Code Issues Pull requests Security Insights. New issue. Jump to bottom. Copy link.

I appreciate if I can help. Handling delays can impact traditional phone networks, but these delays are a larger issue in packetized environments. The following paragraphs discuss the different handling delays and how they affect voice quality.

Two of these speech samples both with 10 ms of delay are then placed within one packet. The packet delay is, therefore, 20 ms. An initial look-ahead of 5 ms occurs when using G. Vendors can decide how many speech samples they want to send in one packet. Because G. In fact, Cisco IOS enables users to choose how many samples to put into each frame. A packet-based network experiences delay for other reasons. Two of these are the time necessary to move the actual packet to the output queue packet switching and queuing delay.

When packets are held in a queue because of congestion on an outbound interface, the result is queuing delay. Queuing delay occurs when more packets are sent out than the interface can handle at a given interval. The actual queuing delay of the output queue is another cause of delay. You should keep this factor to less than 10 ms whenever you can by using whatever queuing methods are optimal for your network. This subject is covered in greater detail in Chapter 8, "Quality of Service.

With the Cisco VoIP implementation, two routers with minimal network delay back to back use only about 60 ms of end-to-end delay. This leaves up to 90 ms of network delay to move the IP packet from source to destination. Figure End-to-End Delay. As shown in Figure , some forms of delay are longer, although accepted, because no other alternatives exist. In satellite transmission, for example, it takes approximately ms for a transmission to reach the satellite, and another ms for it to come back down to Earth.

This results in a total delay of ms. Although the ITU-T recommendation notes that this is outside the acceptable range of voice quality, many conversations occur every day over satellite links. As such, voice quality is often defined as what users will accept and use. In an unmanaged, congested network, queuing delay can add up to two seconds of delay or result in the packet being dropped.

This lengthy period of delay is unacceptable in almost any voice network. Queuing delay is only one component of end-to-end delay. Another way end-to-end delay is affected is through jitter. I would like to receive exclusive offers and hear about products from Cisco Press and its family of brands. I can unsubscribe at any time. Pearson Education, Inc.