What considerations are needed for real-time voice and video applications in a small network?
Verify the infrastructure can carry real-time traffic and configure QoS to minimize latency; RTP and RTCP carry the real-time media, and IP telephony/VoIP need priority delivery.
Carrying voice and video over the same IP network as ordinary data is attractive — one network instead of a separate phone system — but real-time media is unforgiving, so the administrator's first job is to ask whether the infrastructure even has the capacity and capability to carry it. If it does, the media still needs QoS to guarantee priority delivery, otherwise congestion adds latency and the call breaks up. Two protocols do the actual carrying: RTP (Real-Time Transport Protocol) moves the audio/video stream with timing and sequence information, and RTCP (RTP Control Protocol) runs alongside it reporting on quality (loss, jitter, delay) so the endpoints can adapt. It's also worth knowing the two delivery models differ: plain VoIP is cheaper but lower in quality and features, while IP telephony uses dedicated servers for call control and signalling to deliver a richer, PBX-like service.
Network Administrator Considerations:
| Factor | Description |
|---|---|
| Infrastructure | Does the network have the capacity and capability to support real-time applications? |
| VoIP | Voice over IP is typically less expensive than IP Telephony but with reduced quality and features |
| IP Telephony | Uses dedicated servers for call control and signaling |
| Real-Time Applications | Network must support Quality of Service (QoS) to minimize latency issues |
Supporting Protocols:
- RTP (Real-Time Transport Protocol)
- RTCP (Real-Time Transport Control Protocol)
These two protocols support real-time application requirements.
Go deeper:
Wikipedia — Real-time Transport Protocol (RTP) — how RTP carries the media and RTCP monitors quality, the protocols this card names.- Wikipedia — Voice over IP — IP telephony vs VoIP and why real-time voice needs QoS to control latency.