Ports are the usual suspects and scapegoats when something doesn’t work right in any internet connection, whether it’s a multiplayer video game or a stand-up conference call. And even though some ports are not encrypted, many businesses still use them.
What are Ports, and How Do They Work?
In computer networking, ports are like doors in a building. They are numbered from 0 to 65535, and they help a computer figure out where to send different types of information.
When a computer program wants to receive information, it “opens up” or “listens to” a specific port. It then waits for data to come in through that port. Once data arrives at the correct port, the allotted software processes it accordingly.
Some ports have distinct functions, and the Internet Assigned Numbers Authority (IANA) has designated these for specific purposes. For example, port 80 is used for regular web browsing, allowing us to view web pages and other online content. Port 443, on the other hand, is used for secure web browsing.
Port 5060 is a favorite for SIP and VoIP calls
Another port that has been assigned a specific function is port 5060. This port is designated for Session Initiation Protocol (SIP), which is an important standard for making Voice over Internet Protocol (VoIP) calls. SIP enables the setup and management of these calls, making it a crucial component of internet-based phone communication.
Even though it’s not an encrypted port, many businesses use port 5060 for their SIP and VoIP traffic because it’s an industry standard. However, for communications that require more security or control, service providers will often utilize alternative ports to prevent potential attacks that target the default port.
Regardless of the port you use for SIP, the key to security is having the proper protections in place. Thus, businesses should have robust security measures in place, including firewalls, intrusion detection systems, and encryption. It’s also fundamental to carry out regular security audits and updates to address any vulnerabilities that may pop up.
Ports can be blocked with firewalls, or your ISP can block them
Naturally, as security plays a big role in the port conversation, it’s possible for ports to be left open or blocked, typically through firewalls.
Spotify, for example, uses the unconventional port 4070 to stream its tracks. This means that if you ever logged into an airport Wi-Fi and accessed Spotify through your browser via port 443 and were unable to play any songs, it could have been because the network’s admin blocked port 4070.
In other instances, some ISPs will directly block certain ports as part of their service, even without the admin’s explicit knowledge—unless they read the Terms of Service document, which nobody really does, right?
Anyway, blocking ports with a firewall is already a good security measure, but it also comes with some administrative advantages. If you don’t want guests straining your network with streaming platforms or downloading copyrighted content, blocking a port is an effortless way to do this.
Obviously, since ports can be closed out for any reason, an incorrectly blocked port could prevent a VoIP call from connecting—so watch out for those kinds of side effects.
The Choice Between UDP and TCP for Port 5060
Remember that SIP is just a signaling protocol, so it orchestrates the transfer of data, but it doesn’t do any data transfer itself. As such, it merely establishes the rules to begin, finish, and modify a session or call.
The SIP port, 5060, acts as the gateway for SIP communication by facilitating the exchange of signaling information between devices. It supports both UDP (User Datagram Protocol) and TCP (Transmission Control Protocol) connections to transfer data, although there are different implications to using either method for VoIP calls.
Port 5060 UDP for agility
UDP is a way for applications to communicate with each other over the internet without establishing a handshake (a widespread term in telecommunications that signals a conversation or negotiation) before sending data. Unlike other methods, UDP just sends information without even shaking hands. This helps it move quickly, which is great for real-time applications like VoIP calls.
Because of the great match between UDP and VoIP communications, UDP has gained widespread acceptance as the transport protocol for VoIP. As a result, many VoIP service providers and software applications depend on UDP to ensure that voice communication over the internet goes without choppy popping sounds turning up.
However, although UDP is fast and streamlined, it sacrifices some reliability and error-checking. Since it sends data packets without confirming if they reach their destination, there’s no assurance of delivery. Nevertheless, this concession is often acceptable in VoIP because occasional packet loss is less noticeable than significant delays.
Additionally, the tolerability depends on the use case. For example, SIP over UDP is generally not suggested for video conferencing because SIP messages for video systems are too big to be conveyed on a packet-based transport when a stream-based option would serve better.
Port 5060 TCP for reliability
As an alternative to UDP, TCP ensures reliable and error-free data transmission. While it sacrifices agility and efficiency, it’s a safe and tidy option.
Even though TCP prioritizes reliability over speed with its connection-oriented approach, it can still be used for VoIP calls. By establishing a connection and using error-checking measures, TCP ensures that voice data is transmitted accurately. This helps minimize the risk of packet loss or corruption in the process.
Obviously, TCP is not as widely used as UDP for VoIP since it’s more prone to delays. Still, when security is a priority, TCP becomes one of the best alternatives.
Port 5060 vs. Port 5061
Port 5061 is an alternative port for SIP traffic. The fundamental difference with port 5060 is that port 5060 is designed specially for secure communication.
Port 5061 applies TLS (Transport Layer Security), a cryptographic protocol that ensures confidentiality, integrity, and authenticity of data transmitted between two endpoints—such as a client and a server. It’s the tech running behind HTTPS sites so that no one can eavesdrop on your banking password, for example.
TLS functions by creating a secure link between the client and the server through a procedure known as the TLS handshake. In this handshake, the client and server discuss encryption methods and share digital certificates to confirm their identities. Once the secure connection is set up, client-server data is encrypted and thus protected from eavesdroppers known as sniffers or snoopers in cybersecurity jargon.
For added security, TLS uses a combination of symmetric and asymmetric encryption algorithms. Symmetric encryption handles the encryption of the actual data, while asymmetric encryption manages key exchange and authentication processes.
Why TLS is a widespread standard
Because of its advanced security technology, TLS has been widely adopted by the business community to protect almost any communication. It is used and supported by various protocols and applications, including web browsers, email clients, and VoIP systems.
Another reason people use TLS is that it relies on certificates from trusted authorities. For example, when using TLS for secure web browsing, a server presents a digital certificate issued by a trusted Certificate Authority (CA). With so many concerns to keep in mind, it is practical for companies to trust specific cybersecurity validations to expert parties.
Thus, if you want to start relying on TLS and switch to port 5061, you will be opting for a VoIP standard that’s just as widespread as using the unencrypted port 5060.
One key tip is to remember that ports are not encrypted by default. Calling port 5061 encrypted is more of a loosely inaccurate shorthand than it is a literal technical description. Port 5061 has been adopted as the TLS-supporting port for SIP calls, but you still need to add the encryption yourself. You can configure it server-side.
Securing Port 5060
The risks of leaving port 5060 open are the same as those of any available port. Some of the most common attacks it—and the organizations that use it—are subject to include:
- Replay attacks: In a replay attack, someone intercepts and records network traffic, then replays it later to gain unauthorized access or perform malicious actions. With port 5060 open and accessible, attackers could capture and replay SIP messages, potentially leading to unauthorized access to the network.
- Man-in-the-Middle (MITM) Attacks: In MITM attacks, an intruder intercepts and modifies communication between two parties without their knowledge. This means an attacker could intercept and manipulate SIP messages, potentially resulting in unauthorized access, call interception, call hijacking, and any new attack AI technology has brought on.
- Denial-of-Service (DoS) Attacks: A DoS attack is like a digital traffic jam that tries to disrupt a network or service by bombarding it with fake requests. If port 5060 is left open without the right safeguards, businesses might face the risk of DoS attacks. In these situations, attackers could flood the network with SIP requests, causing disruptions to services and making the network temporarily unavailable.
The harm of each of these attacks depends on the industry. Banks and cybersecurity companies, for example, could face disastrous problems if met with a successful MITM attack—not to mention the headlines.
Fortunately, since port 5060 is very mature, there are ways to fight back against these unscrupulous attacks. Some of the tools and methods your business can use to protect SIP and VoIP communications include:
- Firewalls: Consider firewalls to be guardians for your computer network. Businesses can keep out unwanted visitors and stay safe from potential threats by setting up firewalls to allow only approved SIP traffic through port 5060. Security experts recommend constantly regulating open and blocked ports through a firewall and not by other means.
- Session border controllers (SBCs): SBCs are devices or software that ensure VoIP communication stays safe at the network edge. They check the SIP protocol, encrypt data, and manage traffic. SBCs also help keep the network secure by following rules and protecting against attacks.
- Configure device to initiate SIP connection: Instead of opening ports for VoIP in your router, you can configure your device to initiate the SIP connection to the remote server. This approach helps minimize constant attacks and provides additional security for your VoIP communications.
- SIP authentication: SIP authentication ensures that only approved users and devices can use the network for VoIP calls. When businesses use robust authentication methods like two-factor authentication and digital certificates, they’re one step ahead of anyone trying to pass as someone else or spoof a call.
- Encryption: Using VoIP encryption methods like TLS ensures the security of your SIP and VoIP chats. It’s a way of confining your conversations to an ever-moving, unbreakable lockbox so nobody can eavesdrop or tamper with them. The conventional recommendation is to move to port 5061 if you activate TLS or Secure Real-Time Transport Protocol (SRTP).
Keep in mind that there’s no need to choose just one way to secure your calls, as you can combine several methods. When businesses use a mix of protection technologies, they minimize the risks associated with their SIP and VoIP communications.
Why Port 5060 is Still Used Despite Being Unencrypted
Port 5060 remains a popular choice for SIP and VoIP traffic because it’s efficient and familiar, even though there are more secure alternatives—such as port 5061 matched up with TLS. Despite the underlying yet solvable security concerns, port 5060 is also valued for how streamlined it makes VoIP set-ups. Industry experts agree that both UDP and TCP are acceptable options to transfer data.
For instance, if your VoIP provider suggests using port 5060 with UDP, you can go for it even though it’s unencrypted. At the end of the day, its widespread adoption and reliability in facilitating good-quality calls make it a good bet. As long as you take adequate security measures, you can confidently settle on port 5060 for your VoIP calls.
