Comparison between IPTV and OTT

OTT (Over-The-Top) streaming is the delivery of video and audio media streams to connected devices via the Internet. Unlike traditional IPTV, there is no need for a dedicated network or infrastructure provided by the operator, as OTT is transported through regular Internet data protocols and uses the open Internet, on unmanaged networks.

In IPTV, multicast is used as a transport of Linear TV content, saving bandwidth in the operator network. OTT is always unicast traffic, for Linear TV and on demand content, using adaptive streaming technologies

What is the difference between OTT and IPTV?

IPTV – IP work of DVB world

• Traditional IPTV which has been widely deployed by numerous operators, namely those that propose a triple-play ADSL offer to their customers.
• This traditional IPTV is delivered over a dedicated, operator-managed network that is used only for broadcasting TV.
• The operator has full control over the network and can configure certain parameters, such as bandwidth consumption and regularity of packet transportation, to ensure a high level of service quality.
• Traditional IPTV uses TS (transport stream) transmission technology which is based on satellite TV broadcasting and delivers content over UDP in datagram mode.

OTT – TV work of IT world

• OTT TV uses HTTP, the protocol which has been used for decades to transport web pages over the Internet.
• HTTP is based on TCP, a connected transport protocol with more practical features than UDP. It is easier to track a TCP connection, for example. As a result, a TCP connection is easily managed through firewalls, NAT (network address translation), home and office networks.
• It also enables anyone that has sufficient web hosting capacity to broadcast any audio and video media to a worldwide audience over the open Internet.
• HTTP has already been used as a transport solution for video on demand (VOD) media embedded into web pages, especially on Flash-based sites, such as YouTube or Dailymotion.
• However this solution does not use real time streaming, but progressive downloading of one media file, where the browser downloads the file from the HTTP web server and when it has a sufficient amount of data, starts to play the content while downloading the rest of the file.The main drawback to this approach is the length of time it takes to fill the initial buffer.
• Another issue associated with http is streaming quality, which depends on the IP connection.
• Content streaming may be subject to stalling if there are fluctuations in bandwidth, leading to frame freezing. As a consequence, it is nearly impossible to use the solution to broadcast live channels.
• Until recently, live broadcasting was therefore restricted to operator-managed IPTV networks using the UDP multicast protocol.
• The arrival of OTT streaming, however, has brought a new approach and it is now possible to achieve levels of streaming quality over HTTP that allow live content to also be broadcast over the Internet.

Comparison Category	OTT ( Over the Top)	IPTV ( Internet Protocol TV)
Content Delivery	Uses open internet, un-managed network. Open ecosystem	Uses dedicated, managed network. Walled garden ecosystem
Network Type	Delivered from content provider / aggregator to the viewer using open network. Usage of CDN	Closed, proprietary network, accessed via a specific internet service provider
Network Relationship	Without the need for intervening carriage negotiations, or infrastructure investments	Services are delivered on optimized and custom high bandwidth network
Quality of Service (QOS)	Not guaranteed, works under best effort conditions	High quality, reliable network with control over quality of services
Service Examples	Popular Video on Demand services like YouTube, Netflix, Amazon LoveFilm, Hulu, Sky Go, BBC iPlayer etc.	IPTV services like U-Verse (AT&T), Prism TV (CenturyLink)
Delivery Protocol	Delivered over HTTP / TCP, a connected transport protocol. Movement towards adaptive streaming technologies HLS (Apple), Smooth Streaming (MS) and HDS (Adobe)	IPTV uses Transport Stream (TS) transmission technology. Uses RTP (Real time protocol) over UDP, a connectionless protocol
Content Catalog	Widely used for freemium and economical subscription VOD	Used primarily for premium VOD and real time content delivery like broadcast TV
Content Type	Typically not premium in nature due to security, absence of DRM	Premium content
Routing Topology	Unicast (HTTP), Simulated Multicast (UDP/TCP)	Multicast. Initial unicast burst during channel change leading to   Multicast join
Service Category	Complementary Service	Main service, similar to Satellite/Cable TV services
Major Platform Players	OVP (Online Video Platforms) like Kaltura, Brightcove, CDN Players like Akamai, L3, Limelight, Cloud Service Providers like Amazon	TSP ( Telecom Service Providers) and IPTV platform vendors - Microsoft Mediaroom ( now Ericsson) , ALU, Cisco
Key Challenges	Low quality of service, absence of live broadcast, non premium content, unicast delivery model	Expensive, Heavy investment in Bandwidth and infrastructure
Key Benefits	Low cost, flexible model, Easy to manage and operate	High quality of service and quality of experience. Monitoring and control, interactive services

Adaptive Bit Rate (Abr)

As the open Internet is by definition an “unmanaged” network, the end-user bandwidth cannot be controlled. This can lead to low streaming quality and negatively impact the user experience when watching TV. The proposed technology must be adapted for use on a full range of end-user devices (PC web browsers, STB/TV, mobile handsets, digital tablets,smart TVs, etc). 

Currently, there are three big players who propose their own solutions to the challenges of OTT.

Features	MPEG-DASH	Apple HLS	Microsoft Smooth Streaming
Type	Open	Single-vendor control	Single-vendor control
Source Video Codecs	H.264 + others	H.264	H.264, VC-1
Source Audio Codes	AAC + others	AAC, MP3	AAC, WMA
Package/Segment format	MP4 fragments + MPEG-2 TS	MPEG-2 TS	MP4 Fragments
Typical segment duration	Flexible	10 sec	2-4 sec
File storage on server	Contiguous or individual files per segment	İndividual file per segment (pre iOS 5.9)	Contiguous
CDN-Friendly	Yes	Requires chunk carriage optimization	Requires specific IIS-7 origin server
Protection	Flexible	AES-128 enc	PlayReady
Common Encryption	Yes	No	No
Multiple Audio channels	Yes	No	Yes
Subtitle Control	Yes	Partial	Yes
Multiple Audio Support	Yes	V4 Only	Yes
Trick Mode Support	Yes	Partial	Yes