Difference Between SIP and IAX

VoIP, often known as voice over internet protocol, is quickly gaining acceptance as a less expensive calling option. Session Initiation Protocol or SIP, and Inter-Asterisk eXchange, also known as IAX, are two additional protocols that can be used with VoIP. The primary distinction between SIP and IAX is that IAX uses bandwidth far more effectively than SIP does. IAX was developed primarily for this reason. Compared to SIP, adopting IAX enables you to carry more concurrent phone conversations over a given bandwidth.

For those in the telecommunications industry, understanding the differences between Session Initiation Protocol (SIP) and Inter-Asterisk eXchange (IAX) is essential. Knowing how these two protocols interact with one another can help you set up calling systems for maximum efficiency and performance. In this blog post, we will explore the similarities and differences between SIP and IAX, as well as how they each play a role in setting up a secure VoIP connection. Through careful understanding of these two protocols, you will be able to make informed decisions when selecting which one to use for your organization.

Read this article to find out more about SIP and IAX Protocols and how they are different from each other.

What is IAX?

IAX (Inter-Asterisk eXchange) is a Voice over IP protocol that was developed by Digium for use with the Asterisk private branch exchange (PBX) software. IAX uses a single UDP port for both signalling and media, which simplifies firewall configuration. IAX trunking can be used to connect multiple Asterisk servers together to share resources such as Voicemail, hunt groups, and call queues.

IAX supports both unicast and multicast audio, which means that it can be used in situations where NAT or firewalls are present. IAX2, the most recent version of the protocol, adds support for video and text messaging.

IAX has a number of drawbacks, thus it is not without them. The IAX protocol's extension is challenging, which is the first issue. In contrast to SIP, which can be extended quite easily, IAX does not have a generic extension method, therefore any new improvements must be introduced to the specification.

The utilisation of a single port is the second drawback. This is beneficial in one sense since it makes network translation a cinch. This has the drawback of making it simpler for hostile individuals to carry out resource depletion or denial of service attacks. They can defeat the system and keep authorised users from using the service by flooding the IAX port.

What is SIP?

SIP (Session Initiation Protocol) is the most popular VoIP protocol. It's used by the majority of VoIP providers and is compatible with most IP PBX systems. SIP is a text-based protocol that uses ASCII characters, so it's easy to read and debug. SIP is also very flexible, allowing for various codecs and call features.

SIP is only one method of delivering VoIP, but it has the essential advantage of providing a real connection between PBXs, or personal or local area networks, and the main phone network.SIP is a specialised technology that enables VoIP conversations. SIP is an application layer protocol that is employed to transfer many sorts of digital data, including voice messages.

By establishing these links, SIP wiring enables us to separate the system into official and informal sectors. Internet telephone service providers (ITSPs) typically manage open names, whereas privatised sites are connected to a single private server.

SIP is the more widely used of the two when it comes to usage. The use of SIP is supported by almost all VoIP clients. The term "SIP phones" has become more popular as a result of the fact that many hardware manufacturers employ SIP as their primary VoIP handset protocol.

Differences Between SIP and IAX

The following table highlights the major differences between SIP and IAX −

Characteristics	SIP	IAX
Bandwidth	It has the less efficient bandwidth	It has the more efficient bandwidth
Durable	SIP has the less durable	IAX has the extreme durable
Expansion	It has the expansion capability	It doesn’t have the expansion capability
Full Form	It is also known as Session Initiation Protocol	It is also known as Inter-Asterisk Exchange
Protocol	Plain text protocol	Binary Protocol
Usage	Most popular in usage	Less popular is usage
Robustness	Less Robust	More robust

When it comes to choosing a VoIP protocol for your business, you have two main options − SIP and IAX. Both protocols have their own advantages and disadvantages, so it's important to understand the difference between them before making a decision. To help you out, we've put together a comparison table between SIP and IAX.

SIP (Session Initiation Protocol)

• Pro - SIP is the most widely used VoIP protocol, which means that there are more devices and software that support it.

• Con - SIP can be less reliable than other protocols because it uses UDP (User Datagram Protocol), which is less stable than TCP (Transmission Control Protocol).

IAX (Inter-Asterisk eXchange)

• Pro - IAX is a proprietary VoIP protocol developed by digium, the company behind Asterisk. It's designed to work specifically with Asterisk systems, which makes it more reliable than SIP.

• Con - IAX is not as widely adopted as SIP, which means that there are fewer devices and software that support it.

Conclusion

SIP and IAX are two additional technologies that can be utilised with VoIP. Compared to SIP, IAX utilises less bandwidth. IAX is not communicated in plain text, whereas SIP is.

IAX is less flexible than SIP. Threats of resource depletion do not apply to SIP but they do to IAX. IAX is less common than SIP. SIP is used more frequently than either of the other two.

Voice over Internet Protocol, sometimes known as VoIP, is swiftly gaining favour as a cheap substitute for conventional phone calls. Almost all VoIP clients are SIP compliant. The term "SIP phones" originated since SIP is the principal protocol used by many hardware manufacturers for their VoIP telephones.