Do you know which session initiation protocol (SIP) port numbers your voice over IP (VoIP) provider uses? SIP numbers range from zero to 65,535. So it's a good idea to know your actual number instead of guessing. You may not think about your network port until you're facing a problem.

If you wait until an issue strikes, you'll lose valuable downtime looking for your SIP port numbers. Keep your business running smoothly by learning about your network and trunk ports. Doing so helps you troubleshoot the rare problem and get you back up and running in minutes.

Luckily, SIP trunking is secure and reliable. With the right provider, you do not need to perform updates or build new infrastructure. Discover how your VoIP system uses SIP port numbers to route calls fast.

What Is a SIP Port Number?

Software applications and devices use virtual port numbers. Ports control the transfer of data. Each time you send or receive information, a port handles the traffic. To avoid overload, you use different ports for your activities.

For example, consider an airport. Each runway uses a number. Another identification number marks all incoming and outgoing planes. Air traffic controllers rely on protocol and processes to send planes to the right track. When it comes to your communications, each process uses a designated port. If it routes to the wrong port, there may be traffic interference. That's why your video calls go through one port while other data from your computer use different ports.

Your VoIP provider uses SIP trunk ports for your small business phone system. The endpoint is your private branch exchange (PBX) phone system. SIP trunking allows your PBX to use the internet to send and receive calls. So your SIP trunk ports refer to your video, voice and messaging applications. A SIP trunk port number identifies and routes PBX and other application data.

Your cloud phone system uses other types of ports as well. VoIP ports may consist of hardware ports, like USBs and network connection ports.

SIP Traffic Port Numbers

There are three different groups of SIP port numbers. Most SIP traffic goes through port 5060. But with such a wide range of port numbers, it's essential to check the ports for your services. The three groups include:

  • 0 to 1023: Well-known port numbers refer to specific internet services. For instance, port 25 routes email between servers. The term for this is simple mail transfer protocol (SMTP). When you print on a network computer, then you use port 631 for the internet printing protocol (IPP)
  • 1024 to 49151: These are registered ports. The Internet Assigned Numbers Authority (IANA) or Internet Corporation for Assigned Names and Numbers (ICANN) assigns these ports
  • 49152 to 65536: Dynamic or private ports are open for many different uses. These numbers are not registered or assigned. Instead, applications use these ports for temporary purposes

SIP Port Numbers: TCP and UDP

You may hear the acronyms TCP and UDP. Both of these terms refer to internet data transmission. But they're not the same.

TCP is short for transmission control protocol. It's a connection-based transmission. First, you send a data packet. Then, your device receives confirmation of acceptance. This makes TCP reliable. But it's not prudent for high-volume applications. Streaming videos on platforms like YouTube cannot send confirmations for every packet. Doing so would slow down the system. Examples of TCP include:

  • Hypertext transfer protocol (HTTP)
  • Simple mail transfer protocol (SMTP)

UDP stands for user datagram protocol. It's a connectionless transmission. You send data packets but do not receive acknowledgment packets in return. This speeds up your service but does not give you a guarantee that your data was collected. UDP keeps network overhead low. The technology supports:

  • VoIP
  • Internet protocol television (IPTV)

Port 5060 vs. Port 5061

IANA dedicated ports 5060 and 5061 to SIP traffic. But these two SIP port numbers are not equal. The 5060 port signals non-encrypted traffic. 5061 uses transport layer security (TLS) for encrypted traffic signaling.

Most VoIP calls go through port 5060. This port uses both TCP and UDP. It accepts data and listens for incoming communication. A 5061 port only allows TCP connections.

Network Elements

Your cloud-based phone system uses many behind-the-scenes elements. When troubleshooting a problem, you may come across unfamiliar terms. To get your service up and running, it's vital to know what each word means. Often, your provider walks you through these functions. They may offer extra materials online in the form of FAQs or a knowledge base.

User Agent

The term user agent encompasses all software that supports a user's needs. Each piece of software or device has a unique user agent string identifier. User agents include:

  • Operating systems
  • Email readers
  • Web browser
  • Social media applications

A SIP softphone or telephone asks for and receives SIP responses. An example of a user agent client (UAC) is a softphone. Your VoIP device sends its request to a user agent server (UAS). This model supports peer-to-peer calling.

Proxy Server

The main role of a proxy server is routing. SIP proxies route requests and responses. It's the go-between for user agent servers and user agent clients. Your proxy server also double-checks that users have permission to make or get calls.

Redirect Server

Almost everyone has come into contact with a redirect web page while using the internet. You may not know it because you type in the original web address. The redirect page automatically sends you to the new page. It works almost the same way when using a VoIP phone service. When you call a number that has changed, a redirect server gives you the new information.


Servers can be both proxy and registrar. The difference is that a registrar gets user registrations. User registrations consist of location information like IP addresses. When a registrar server receives location data, it adds it to a database. This database is called the location service. Proxy and registrar servers use the database to route requests to the right spot.

Session Border Controller (SBC)

VoIP services use a session border controller. This protects networks and assists with the quality of service. SBC is a device that controls signaling and call management. It helps set up and conduct calls. This device scans all SIP-enabled traffic to keep your network secure. Plus, an SBC prevents disruptions during communications.


Gateways are the doorway between different phone systems. Both public switched telephone networks (PSTN) and VoIP gateways exist. Gateways receive information. Then, the device transmits data to the network. For example, a VoIP gateway transforms fax and voice calls into packets that a PSTN sends.

PSTN and VoIP gateways work in similar ways. But your VoIP gateway comes in two versions to enable call routing between a cloud and wired network.

  • A digital VoIP gateway connects T1 lines and more to your small business phone system
  • An analog VoIP gateway connects standard analog landlines to your cloud phone service

SIP Port Numbers and SIP Trunking

SIP trunking benefits your business in many ways. First, it delivers big cost savings. You do not need to build and maintain physical wiring and hardware. Nor do you need a connection to your local phone company. Instead, use unified communications to connect all your devices, including cell phones. SIP trunking gives your company enterprise-level features to serve your customers better. A VoIP phone system provides many benefits, such as:

  • Less IT expenses as your provider handles updates and maintenance
  • Lower costs for long-distance calls, so fewer surprises on your monthly bill
  • Easy to add or delete lines during high-volume times
  • Fast setup with no major hardware needed

If you want to connect different networks or start fresh with a cloud phone system, consider choosing 8x8. Simply use a mobile or web portal to access details about your business phone system. Plus, you can improve customer service and communications with a SIP trunk call manager.

Why Choose 8x8?

Boost efficiency and stay connected using unified communications. 8x8's solutions allow you to hold conversations on any device and from anywhere. Our reliable and secure cloud network puts incredible features at your fingertips like:

With 8x8, security comes first. We provide security compliance certificates to support your business's regulatory requirements. Certificates include:

  • Federal Information Security Management Act (FISMA)
  • Sarbanes-Oxley Act (SOX)
  • Health Insurance Portability and Accountability Act of 1996 (HIPAA)

Meet your customer and employee needs by investing in VoIP technology. Our team works with yours to design the right phone system for your company. With SIP port and SIP trunk numbers, you send and receive high-quality voice and video calls. Plus, it's easy to scale your services up or down with just a few clicks.

Your cloud software-based PBX provider and available feature set directly affect your relationships with your clients, which directly affect your business's bottom line. Choose a superior cloud system and ensure that this effect is for the better. Fill out our online form today or call us at 1-844-673-8419 to request a no-obligation quote from an 8x8 product specialist.

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