SIP vs VoIP – everything you need to know
As business communication continues to evolve beyond traditional phone lines, it can feel hard to keep up with what’s best for your business – especially when the terminology is used so interchangeably and without clear definitions.
But don’t worry, we’re here to help.
In this article, we’re taking an in-depth look at two communication technologies – SIP (Session Initiation Protocol) and VoIP (Voice over Internet Protocol). And we’ll explore the similarities, differences, and what that means for you.
What is VoIP?
VoIP is the technology that enables voice communications over IP (Internet Protocol) networks.
Rather than using traditional circuit-switched telephone networks to transmit the voice signal, it transforms it into digital data packets. These packets then travel over IP networks, before being converted back into sound when they are received.
It’s worth noting that when businesses talk about VoIP, they’re usually talking about hosted VoIP – ready-to-use, hosted phone packages. And that’s the definition that’s the definition that we’ll be using this blog.
What is SIP?
SIP is a signaling protocol that manages real-time communication sessions, including VoIP sessions.
Essentially, it works as a handshake between the devices that use VoIP to transmit calls, but it doesn’t transmit the voice signal itself.
When businesses refer to SIP as a practical solution, they typically mean SIP trunking – a way of connecting SIP services to existing PBX (Private Branch Exchange) systems – and that’s what we’ll be doing here too.
If you want more details on SIP trunking, you can check out our blog where we explore it more in depth.
What are the differences between hosted VoIP and SIP trunking?
Aside from their technical distinctions, there are several other differences between hosted VoIP and SIP trunking, including:
Multimedia capabilities:
Implementation needs:
SIP trunking is ideal for organizations that want to modernize their current setup without new investment. But businesses that want ready-to-go solutions that don’t rely on their existing technology may favor hosted VoIP services.
Technical flexibility:
Because it uses open standards, SIP trunking offers greater interoperability between vendors and systems. While hosted VoIP can use proprietary implementations as well as SIP to transfer voice signals.
Hosted VoIP’s advantages and disadvantages
Advantages
Simplicity:
Hosted VoIP is ready to use, quick to deploy and adopt, and has its maintenance, updates, and troubleshooting handled by the supplier.
Comprehensive features:
From mobile apps that extend capabilities to other devices to fee-free updates, the comprehensive features that come with hosted VoIP’s base packages are a big advantage.
Minimal expertise required:
With 24/7 support, automatic updates, and built-in redundancy and disaster recovery, hosted VoIP makes it easy to keep setups secure with minimal input.
Modern UC capabilities:
Integrated video, collaboration, and productivity tools, alongside presence information, help keep experiences consistent across devices.
Flexibility:
Hosted VoIP is easy to add to new locations without new investment, enabling businesses to maintain existing phone numbers on mobile devices.
Disadvantages
Less control:
Hosted VoIP has fewer options for customization, with potentially limited configurations and a dependence on the provider’s update schedule.
Proprietary implementations can mean there are costs for switching.
Feature limitations:
To access advanced features, you may have to commit to higher-tier plans.
SIP trunking’s advantages and disadvantages
SIP trunking’s advantages
Easy to scale:
Channels can be added and removed quickly without service calls, meaning capacity can be scaled according to need rather than user count.
Advanced UC:
SIP trunking supports multimedia and enhanced call routing, and it integrates with business and CRM systems for smoother workflows.
Interoperability:
As an open standard, SIP works with any compliant device, software, or platform – making migration between providers easier and helping to future-proof investments.
Enhanced continuity:
Failover capabilities and redundancy options make it easy to maintain service, with call forwarding supporting reachability for mobile teams.
Greater control:
SIP trunking offers direct control over quality-of-service configuration, with the ability to customize security policies and integrate with legacy business systems.
SIP trunking’s disadvantages
Complex solution:
SIP trunking can require dedicated IT resources and technical expertise to implement, configure, and manage.
System dependent:
SIP trunking needs an existing PBX system to run.
Limited provider support:
SIP trunking providers tend to only offer support for their own service.
What is call quality like for hosted VoIP and SIP trunking?
For both hosted VoIP and SIP trunking, it’s the network quality, not the technologies themselves, that dictates the call experience.
The network quality factors that can affect hosted VoIP and SIP trunking include:
- Available bandwidth
- Congestion and packet loss
- Latency and delay
- Quality-of-service implementations
- Connection consistency and reliability
Both hosted VoIP and SIP trunking can deliver exceptional call quality, but this takes proper implementation and network configuration – something an expert partner can help with.
Cost comparison between hosted VoIP and SIP trunking
Whichever option you choose, there are cost implications for both hosted VoIP and SIP trunking solutions.
We’ve outlined some of the general points below, but please be aware that these will vary by provider, so it’s worth creating your own comparison table when evaluating your options.
| Hosted VoIP | SIP trunking |
Pricing model | Monthly per-user subscription. | Monthly per-channel or per-trunk fee. |
Call charges | Included within subscription. | Variable international rates, often unlimited domestic calling. |
Setup costs | Typically, just setup fees for users. | Potential IP-PBX upgrade required depending on system age. |
Ongoing costs | None, aside from monthly subscription. | Equipment maintenance and IT staff costs for management. |
Efficiencies and savings | No capital investment required for telecom equipment. Reduces IT overheads for system management. Single bill inclusive of support, equipment, and calls. | Lower costs compared to traditional phone lines. Cost efficiency is increased if existing PBX in place with no upgrade required. Long-distance call cost often reduced compared to traditional phone lines. |
Security considerations for hosted VoIP and SIP trunking
As both hosted VoIP and SIP trunking rely on IP networks, they face similar security challenges. These can include:
- Eavesdropping
- Unauthorized use
- Denial of Service attacks
- ID spoofing
- Registration hijacking
And while the threats are the same, businesses have different options for protecting themselves against them, depending on whether they are using hosted VoIP or SIP trunking.
Hosted VoIP security considerations
For hosted VoIP services, security should be handled by the service provider.
Here’s what you should expect them to deliver:
- Relevant security certifications such as SOC 2 and ISO 27001
- Physical security and geographic redundancy for data centers
- Compliance certifications like HIPAA, PCI-DSS, and GDPR for regulated industries
- Reasonable service level agreements and incident response procedures
- Encryption for data at rest and in transit
- Options for multi-factor authentication
SIP trunking security considerations
With SIP trunking, you’ll be responsible for implementing your own security measures.
Here’s what you should have in place:
- Session Border Controllers for filtering traffic and hiding topology
- SIP-specific firewall configurations
- Media and signaling encryption
- Strong authentication like complex passwords and certificate-based authentication methods
- Regular penetration testing and security audits
- Intrusion detection systems with monitoring for unusual activity
Let an expert bring you your ideal solution
At Sipcom, we concentrate on getting you the right technology, tailored to your needs.
Our UC specialists are ready to help you decide between hosted VoIP, SIP trunking, or a hybrid solution, so you get the telecom technology that works best for you.
If you’d like to get started, get in touch with the team.
Discuss our UC skills
Looking to sell hosted VoIP or SIP trunking solutions?
From sales materials to specialist knowledge, we’ve got all the resources you need to help you get started.
Just head to our website to explore what partnering with us can do for your business.
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Frequently asked questions about SIP vs VoIP
What is the difference between SIP and VoIP?
In general definitions, SIP and VoIP work together – not as competing technologies.
VoIP enables voice communication sessions over IP networks, while SIP manages these sessions.
However, when businesses refer to VoIP they are usually talking about hosted VoIP – ready-to-use, hosted phone packages.
And when they talk about SIP, they are typically discussing SIP trunking, a way of connecting SIP services to existing PBX systems.
Is SIP required for VoIP?
SIP is flexible and widely supported, so it’s become the standard for modern VoIP services.
It is not technically required to enable VoIP, as other protocols are available, however, without it, features like video conferencing and advanced call management are more difficult to implement.
Which is better, SIP or VoIP?
As general technologies, SIP and VoIP are complementary – not in competition.
VoIP uses SIP to manage the voice communication sessions that it sends over IP networks. The real comparison is between services based on these technologies – hosted VoIP and SIP trunking. Deciding which is better for your business depends on your existing setup and needs.
SIP trunking offers cost savings and control to organizations that have existing PBX systems. Whereas hosted VoIP is suited to businesses who need ready-to-use solutions that require minimal IT oversight.
Is SIP more secure than VoIP?
The security of your solution depends on implementation, rather than the technology itself.
Both SIP trunking and hosted VoIP use IP networks, so they share similar security threats.
As SIP trunking security is handled by the business that implements it, it offers more control but requires expertise to manage. Whereas hosted VoIP security is handled by the provider, meaning it’s easier to manage but comes with less control as a result.
With the correct implementation, both solutions can be highly secure.
Can I use SIP and VoIP together?
Yes, it’s possible to use both technologies together, especially as SIP is commonly used to enable VoIP sessions.
Many organizations use a hybrid approach. This involves SIP trunking in their main office utilizing their existing PBX, with hosted VoIP used for branch offices and remote working hubs.
Are SIP and VoIP compatible with traditional phone systems?
SIP trunking is designed to connect with existing traditional PBX systems.
But for this to work, it requires an IP-enabled PBX or analog-to-digital conversion equipment.
In contrast, hosted VoIP services are designed to replace, not integrate with, existing phone systems.
How does call quality compare between SIP and VoIP?
As both technologies transmit voice as data packets over IP networks, the call quality is comparable for both when implemented correctly.
Issues affecting quality are dependent on the network they run on, rather than the technology itself.
