Firewall and network requirements

ConnectUC connects out to the Dial Raven phone system over the internet. If a firewall blocks these connections, you’ll see sign-in problems, calls that won’t connect, or one-way audio. Share this page with whoever manages your network.

Ports ConnectUC uses

These are outbound connections that start from the computer running ConnectUC.

Purpose	Port	Protocol
App connection, events, and updates	443	TCP and UDP
Call setup (signaling)	9002	TCP
Call audio	30000 to 40000	UDP
Team chat	443	TCP

All of this traffic is encrypted. Signaling travels over secure WebSockets, and call audio is encrypted too.

Heads up: If outbound port 9002 TCP is blocked, ConnectUC shows an orange banner at the top that says “Unable to connect to calling services”, with a Reconnect link, and calls won’t connect.

Firewall settings to check

• Allow outbound traffic on the ports above.
• Keep connections open. ConnectUC holds long-running connections. If your firewall closes idle TCP connections quickly, set the timeout to about 60 minutes or more.
• DNS must work properly. Bad DNS settings can stop calls from connecting.
• Avoid filtering or inspecting this traffic. Web filters and SSL inspection can break the connection.

Windows computers

The Windows Firewall can block the desktop app from receiving traffic. Make sure ConnectUC (connectuc.exe) is allowed on the Private network profile.

Tip: Some web browsers and computers put idle tabs to sleep to save power. Keep uc.dialraven.com on your browser’s list of sites that never sleep so the connection stays up.

Symptoms and what they usually mean

You see	Likely cause
Can’t place or receive calls, orange “Unable to connect to calling services” banner	Port 9002 TCP blocked, or DNS problem
One-way or no audio	UDP 30000 to 40000 blocked, or a local firewall
Call history, texts, or voicemail don’t update until refresh	The 443 connection was dropped, often by a short firewall timeout
Chat messages don’t send	Outbound 443 to the chat service blocked

Desk phones

Desk phones connect differently from the ConnectUC app. On most networks they work with no firewall changes at all, because each phone opens its own connection out to Dial Raven. If your firewall blocks outbound traffic by default, allow these outbound connections from the phones:

Purpose	Port	Protocol
Phone setup downloads and web pages	80 and 443	TCP
Call setup (signaling)	5060	UDP
Call audio	17000 to 35999	UDP

Then check these router and firewall settings:

• Turn off SIP ALG. It may be called SIP Helper, SIP Transformer, or something similar, and it can live on your modem as well as your firewall. It rewrites phone traffic and causes one-way audio, dropped calls, phones that keep ringing after you answer, and phones that lose their connection. Some equipment hides the setting or can’t turn it off, in which case the equipment needs replacing.
• Set the UDP timeout to 30 to 60 seconds. If it’s shorter, calls may go straight to voicemail or drop at regular intervals, such as at 17 or 32 minutes.
• Leave MTU at 1500. A smaller value can stop some calls from connecting at all.
• Turn off stateful packet inspection (SPI) for phone traffic if your firewall offers it. Like SIP ALG, it can interfere with phones.
• Don’t let DNS filtering block “infrastructure” categories. Some DNS filtering services block the addresses phones use to find Dial Raven.
• Using your internet provider’s router? If you also run your own router or firewall, put the provider’s router in bridge mode and turn off its Wi-Fi and firewall, so only one device handles your traffic.
• Avoid double NAT (two routers in a row, each translating addresses) when you can. It usually works, but it’s one more thing that can go wrong.

If phones on your network still won’t connect, see Desk phone not working.

Get the best call quality

These steps aren’t required, but they’re the best protection against choppy calls, especially on a busy network:

• Prioritize voice traffic. Turn on QoS or traffic shaping on your router or firewall, and put phone traffic first.
• Separate your phones. A voice VLAN keeps phone traffic away from computers and other devices.
• Tag voice traffic. If your equipment supports DSCP marking, use 46 for call audio and 26 for call setup.
• Plan bandwidth. Each call needs under 100 kbps in each direction. A steady connection matters more than a fast one.
• Know the targets. Good call quality needs packet loss under 1%, latency under 150 ms, and low jitter. The Network Health Check measures all three.

Common questions

Do you have a list of addresses to allow?

Contact support for the current list of server addresses to allow for your account. Addresses can change, so we keep the list up to date for you. Where your firewall allows it, allow by domain name rather than by IP address.

After a power outage, our phones won’t connect. Why?

Routers, firewalls, and switches sometimes come back from a power cut with stale settings that block phones. Restart your modem first, then your router or firewall, then your network switches, then the phones. A battery backup (UPS) on your network equipment helps prevent this.

Does ConnectUC work in a virtual desktop like Citrix?

No. ConnectUC isn’t designed for virtual desktop environments. Install it directly on the user’s computer.

How do I test after making changes?

Run the Network Health Check, then have a user sign out of ConnectUC, sign back in, and make a test call.

Related articles

• Choppy or one-way audio
• ConnectUC won’t sign in
• Contact Dial Raven support