UCaaS Guide

RingCentral SIP Troubleshooting

8 min read  ·  Updated April 2026

RingCentral runs SIP under the hood for all voice calls. When calls fail, audio is choppy, or connectivity breaks, the root cause appears in the SIP signaling and RTP streams. Here is how to find it using RingCentral tools and SIP analysis.

SIPSymposium is an independent platform not affiliated with or endorsed by any product or company mentioned in this guide.

In this guide

1. RingCentral voice architecture

RingCentral MVP (now RingEX) uses SIP for all voice calls. RingCentral softphones, desk phones, and the mobile app all register to RingCentral SIP servers using SIP over UDP, TCP, or TLS. Media flows through RingCentral media servers with SRTP encryption.

Understanding the architecture helps with troubleshooting:

2. RingCentral Analytics and QoS dashboard

RingCentral Admin Portal → Analytics → Quality of Service is the primary tool for diagnosing call quality issues.

Key metrics to check

MetricGoodPoor
MOS Score4.0+Below 3.5
Packet Loss<1%Above 2%
Jitter<30msAbove 50ms
Latency (RTT)<150msAbove 300ms

Filter by user, date range, or device type. Click any call to see per-minute quality graphs showing exactly when quality degraded during the call. This helps correlate quality issues with network events (backup job starting, video call beginning).

Live Reports

Analytics → Live Reports shows active calls with real-time quality metrics. Use this to identify affected users during an active quality incident.

3. Diagnosing call failures

Admin Portal call logs

Admin Portal → Reports → Call Log. Filter by user, extension, or time range. Failed calls show result codes:

ResultMeaning
MissedCall rang but not answered
No AnswerCall went to voicemail
FailedCall could not be connected
BlockedCall rejected by call blocking rule

Common call failure causes

Issue 01
Outbound calls failing to external numbers
Check the user outbound calling permissions (Admin Portal → Users → user → Phone and Extensions → Outbound Calling). Verify international calling is enabled if needed. Check if the number format is correct — US numbers should be dialed as 10 digits.
Issue 02
Inbound calls not reaching extension
Check call routing rules (Admin Portal → Phone Numbers → select number → Call Handling). Verify the number routes to the correct extension or call queue. Check business hours settings — calls outside business hours may route to voicemail.

4. Audio quality troubleshooting

RingCentral audio quality issues are almost always network-related. Steps to diagnose:

  1. Check QoS dashboard first — identify if quality is poor for one user or many
  2. Test network path — run RingCentral Network Requirements Tool (available in admin portal)
  3. Check for bandwidth contention — run a network test during a call to see if bandwidth usage correlates with quality drops
  4. Test wired vs wireless — Wi-Fi interference causes jitter; test with wired connection to isolate

RingCentral network requirements

; Ports required for RingCentral ; SIP signaling: UDP/TCP 5060, TCP 5090, UDP 5004 ; Media (RTP/SRTP): UDP 16384-16482 ; HTTPS: TCP 443 ; STUN: UDP 3478 ; Allow RingCentral media server IP ranges ; See: https://support.ringcentral.com/article/Network-Admin.html ; Key ranges include media.ringcentral.com and SIP server IPs

5. RingCentral BYOC and SIP trunk issues

RingCentral BYOC (Bring Your Own Carrier) connects your SBC to RingCentral for PSTN calls. Common BYOC issues:

BYOC Issue 01
SBC showing disconnected in RC admin
RingCentral cannot reach your SBC. Check that your SBC public IP is in the RingCentral BYOC configuration, TLS port 5061 is open inbound from RingCentral IP ranges, and the SBC certificate is valid (public CA, not self-signed).
BYOC Issue 02
Calls connect but no audio
SRTP mismatch between your SBC and RingCentral. RingCentral requires SRTP on the BYOC leg. Verify your SBC is configured for SRTP and that the crypto profile matches RingCentral requirements.

6. Capturing SIP traces for RingCentral

RingCentral does not expose raw SIP traces to customers. For BYOC/SBC deployments, capture on the SBC side:

; Capture RingCentral BYOC traffic on SBC tcpdump -i eth0 -w /tmp/rc-byoc.pcap host [ringcentral-sip-proxy-ip] and port 5061 ; For softphone issues, use Wireshark on the endpoint ; Filter: sip || rtp ; RingCentral Network Requirements Tool ; Admin Portal → Tools → Network Requirements Test ; Runs connectivity and quality tests to RC servers

For softphone quality issues, enable RingCentral app logging: Settings → Help → Diagnostics → Enable Logging. Send logs to RingCentral support for analysis.

Frequently asked questions

How do I check call quality in RingCentral?

In RingCentral Admin Portal go to Analytics → Quality of Service. This shows per-call MOS scores, packet loss, jitter, and latency. Filter by user, date, or device. Click any call to see per-minute quality graphs. Target MOS above 4.0, packet loss below 1%, jitter below 30ms. For live issues use Analytics → Live Reports.

Why are RingCentral calls failing?

Check Admin Portal → Reports → Call Log for failed calls and result codes. Common causes: outbound calling not enabled for the user, international calling not permitted, number format wrong, or call routing rules misconfigured. For BYOC deployments check SBC connectivity and certificate validity in the BYOC configuration page.

How do I fix choppy audio on RingCentral?

RingCentral choppy audio is a network issue. Run the Network Requirements Test in Admin Portal → Tools. Check for jitter above 30ms and packet loss above 1% in the QoS dashboard. Common fixes: implement QoS DSCP marking for RingCentral traffic, check for bandwidth contention, test wired vs wireless, and ensure UDP ports 16384-16482 are open bidirectionally for RTP media.

Having RingCentral call quality issues?

For BYOC deployments, capture SIP from your SBC and upload to SIPSymposium. The analyzer identifies codec mismatches, SRTP failures, and media path issues at the RingCentral boundary.

Analyze my trace Create free account
Related guides