Processing Delay

• This is a major delay category, which is usually observed within those digital systems, that performs gateway operations in digital communication systems. For instance, in data networks, routers (devices for interconnecting two different networks) are responsible for this type of delay, which is caused because each of these devices checks, decodes and accordingly forwards/blocks the processing information associated with the incoming and outgoing data bits. Further, in digital telephone and cellular networks, this type of delay is usually observed at gateway switches or exchanges, which have the task of interconnecting different individual exchanges with each other.
  
  

Buffering Delay

• Buffering delays are also caused at routing positions within digital communication networks. This type of delay usually arises because of increased numbers of data packets incoming/outgoing through a router, and for this reason, routers queue and process each data packet on a first-come, first-serve basis. Buffering delays are also observed during voice and video communication at computing devices, during which the integrated microprocessor translates a large number of discrete data bits (bundled as packets) to be presented as continuous information to the user at once.
  
  

Packetization Delay

• This type of delay is specifically associated with voice networking digital systems, into which speech signals are translated and coded as data packets to be transmitted forward. During this type of delay, voice frequencies are converted into digital pulses, addressed according to the sequence into which they are received and bundled into packets for transmission.
  
  

Serialization Delay

• Serialization delay is commonly referred to as the period of time into which the serialization process of data packets is carried out at the switching and routing nodes of a data communication network. The process of serialization refers to the activity of numbering and storing of data bits at the switching (or processing) ends of a network, and is usually taken as the shortest and least significant delay that occurs during the electronic communication process.
  
  

Transmission Delay

• This type of delay is usually caused by the collective contribution of serialization, packetization and buffering and other minor delays within a data communication network. Its specific sources are usually hard to track, but it is normally considered to be resulting from the overall processing times taken by networking nodes, along with the carrier over which information is exchanged. It is also referred to as transmission delay, which is the measure of total time that network resources take to transmit data bits.
  
  

De-Jitter Delay

• Jitter is a form of variation or distortion that occurs within a digital data pulse from any external or internal source. To eliminate this unwanted variation, routers and gateways in a voice/data network have specific circuits integrated within their architecture, which work toward reshaping the data signal in its original format. This process of reshaping or signal reconstruction is called de-jittering, and it causes a minor delay within process of communication. The source of jitter can be external as well as internal, ranging from device malfunction and carrier damage to surrounding environment\s effects over the network.
  
  

Propagation Delay

• This type of delay presents the total time that a data signal spends in traveling between transmitter and receiver in a digital communication network. More precisely, this is the delay caused by medium or link (wireless/wired) over which data is exchanged between two communicating nodes, and is an effective contributor in determining the efficiency of a communication network.