VOS3000 No Media Hangup: Smart Auto-Disconnect for Ghost Calls
In wholesale VoIP operations, few problems are as insidious and costly as ghost calls โ calls that remain connected in SIP signaling but have no RTP media flowing. These phantom sessions silently consume concurrent call capacity, inflate CDR durations, and generate billing disputes that erode customer trust. The VOS3000 no media hangup feature, configured through the SS_NOMEDIAHANGUPTIME system parameter documented in VOS3000 Manual Section 4.3.5.2, provides a Smart automatic disconnect mechanism that monitors RTP streams and terminates calls when media stops flowing for a configurable period.
This comprehensive guide explains what ghost calls are, how they impact your VoIP business, and how to configure VOS3000 no media hangup to automatically clean up dead call sessions. Whether you are dealing with NAT timeout issues, endpoint crashes, or one-way audio scenarios that leave zombie calls on your server, this guide covers the complete configuration, testing, and troubleshooting process. For professional assistance with VOS3000 ghost call prevention, contact us on WhatsApp at +8801911119966.
Table of Contents
What Are Ghost Calls in VoIP?
A ghost call is a VoIP session that remains established in SIP signaling but has no active RTP media stream. The SIP dialog is still valid โ the call appears as “answered” and “connected” in the system โ but no voice packets are flowing between the endpoints. From the VOS3000 softswitch perspective, the call slot is occupied, the CDR timer is running, and the session counts against your concurrent call limit, but there is no actual voice communication happening.
Ghost calls are particularly dangerous because they are invisible to the caller and callee. Neither party is aware that a call session is still open on the server. The SIP signaling path may have been maintained through keepalive messages or simply because neither side sent a BYE message, while the RTP media path has completely died. The result is a zombie call that wastes resources and corrupts billing data until someone or something terminates it.
Why Ghost Calls Are a Serious Problem
Ghost calls create multiple layers of problems for VoIP operators:
- Wasted concurrent call capacity: Every ghost call occupies a license slot that could be used for a real call. During network instability events, hundreds of ghost calls can accumulate, exhausting your concurrent call capacity and blocking legitimate traffic
- Incorrect billing: CDR records show the full duration from answer to disconnect, including the period when no media was flowing. Customers are billed for dead air time, leading to disputes and chargebacks
- Inflated CDR durations: Ghost calls can last for hours because neither endpoint sends a BYE. CDR records show extremely long call durations with no corresponding voice activity, distorting traffic analytics
- Billing disputes: When customers analyze their CDRs and find calls lasting hours with no conversation, they dispute the charges. Resolving these disputes consumes time and damages business relationships
- Resource exhaustion: Each ghost call maintains state in the VOS3000 media relay, consuming memory and processing resources that should be available for active calls
For a deeper understanding of VOS3000 media handling, see our VOS3000 RTP media guide.
How Ghost Calls Occur: Causes and Symptoms
Understanding the root causes of ghost calls is essential for effective prevention. Ghost calls typically occur when the SIP signaling path survives while the RTP media path fails. This section covers the most common causes and their telltale symptoms.
| ๐ป Cause | ๐ Description | ๐ Symptom in CDR | โ ๏ธ Impact Level |
|---|---|---|---|
| Network connectivity loss | Internet link failure between VOS3000 and one endpoint; SIP path via alternate route but RTP direct path broken | Call duration extends far beyond normal; no media packets during outage window | High โ multiple simultaneous ghost calls during outage |
| NAT timeout | NAT device drops RTP pinhole mapping due to inactivity; SIP signaling on separate pinhole survives | One-way audio progressing to no audio; call remains connected indefinitely | Medium โ affects specific endpoint pairs behind NAT |
| Endpoint crash or reboot | IP phone, gateway, or softphone crashes without sending SIP BYE or CANCEL | CDR shows call starting normally then continuing for extended period with no media | Medium โ sporadic occurrence depending on endpoint stability |
| One-way audio scenario | Media flows in one direction only; one endpoint sends RTP but the other cannot receive or respond | Asymmetric RTP; one direction shows zero packets in capture | Medium โ common with firewall and NAT misconfigurations |
| Firewall state table overflow | Firewall drops RTP session state due to table overflow; SIP session on different port survives | Sudden media loss during peak traffic; call remains in signaling state | High โ affects many calls simultaneously during peak hours |
| Codec renegotiation failure | Re-INVITE for codec change fails on media path but succeeds on signaling path | Call connected with initial codec, then media stops after re-INVITE | Low โ rare but difficult to diagnose |
| SIP ALG interference | Router SIP ALG modifies SDP in ways that break RTP path while keeping SIP signaling functional | Call answers but no RTP flows from the start; stays connected until timeout | Medium โ common with consumer-grade routers |
How VOS3000 No Media Hangup Works
The VOS3000 no media hangup feature provides an automatic mechanism to detect and terminate ghost calls. When enabled, VOS3000 continuously monitors the RTP media stream for each active call. If no RTP packets are received for the duration specified by the SS_NOMEDIAHANGUPTIME parameter, VOS3000 automatically sends a SIP BYE message to terminate the call and close the session.
The monitoring process works at the media relay level. When VOS3000 operates in Media Proxy mode, all RTP packets pass through the VOS3000 server. The media relay component tracks RTP packet reception for each active call session. If the RTP stream for a call stops โ meaning no RTP packets are received on either the caller or callee media port for the configured timeout period โ the system considers the call dead and initiates automatic disconnect by sending a SIP BYE to both endpoints.
This Smart detection mechanism is fundamentally different from the SIP session timer. The session timer operates at the SIP signaling layer and detects when SIP re-INVITE or UPDATE refreshes fail. The no media hangup operates at the RTP media layer and detects when voice packets stop flowing, regardless of whether the SIP signaling path is still alive. For details on the session timer mechanism, see our VOS3000 session timer 32-second drop guide.
The Auto-Disconnect Process Step by Step
When VOS3000 detects that no RTP media has been received for a call within the configured timeout, the following sequence occurs:
- RTP monitoring: The VOS3000 media relay continuously tracks RTP packet reception for every active call session
- Timeout detection: When no RTP packets are received for SS_NOMEDIAHANGUPTIME seconds on a call, the media relay flags the session as dead
- BYE generation: VOS3000 generates a SIP BYE request for the affected call and sends it to both the caller and callee endpoints
- Session teardown: The SIP dialog is terminated, media relay ports are released, and the call session state is cleaned up
- CDR closure: The CDR record is finalized with the disconnect time and appropriate cause code, recording the actual duration the call remained active
VOS3000 No Media Hangup Detection Flow: 1. Call established (SIP 200 OK received and ACKed) 2. RTP media proxy active โ packets flowing in both directions 3. RTP stream stops (no packets received from either endpoint) 4. Timer starts: counting seconds since last RTP packet received 5. Timer reaches SS_NOMEDIAHANGUPTIME seconds โ call flagged as ghost 6. VOS3000 sends SIP BYE to both endpoints 7. Call session terminated, media ports released, CDR closed Key Requirement: Media Proxy mode must be active for RTP monitoring. Direct media bypass mode does NOT support no media hangup detection.
For help configuring Media Proxy mode to support no media hangup detection, refer to the VOS3000 system parameter documentation or contact your system administrator.
Configuring SS_NOMEDIAHANGUPTIME in VOS3000
The SS_NOMEDIAHANGUPTIME parameter is the core configuration for the VOS3000 no media hangup feature. It defines the number of seconds VOS3000 waits without receiving any RTP packets before automatically disconnecting the call. This parameter is configured in the VOS3000 softswitch system parameters, as documented in VOS3000 Manual Section 4.3.5.2.
Navigating to the Configuration
To configure SS_NOMEDIAHANGUPTIME, follow these steps:
- Log in to VOS3000: Access the VOS3000 client application with an administrator account
- Navigate to System Parameters: Go to Operation Management > Softswitch Management > Additional Settings > System Parameter
- Locate SS_NOMEDIAHANGUPTIME: Search for the parameter name in the system parameter list
- Set the timeout value: Enter the desired number of seconds (see configuration values table below)
- Save and apply: Save the parameter change โ the setting takes effect for new calls; existing calls use the previous value
| โ๏ธ Parameter Value | ๐ Behavior | ๐ฏ Use Case | โ ๏ธ Consideration |
|---|---|---|---|
| 0 | No media hangup disabled โ ghost calls never auto-disconnected | When relying entirely on SIP session timer for call cleanup | Ghost calls will persist indefinitely without session timer |
| 30 | Disconnect after 30 seconds of no RTP media | Aggressive cleanup for high-capacity systems where every slot counts | May disconnect legitimate calls with long silent periods (hold, mute) |
| 60 | Disconnect after 60 seconds of no RTP media | Balanced setting for most wholesale VoIP deployments | Good balance between cleanup speed and legitimate silence tolerance |
| 90 | Disconnect after 90 seconds of no RTP media | Conservative setting for environments with frequent short silent periods | Ghost calls may persist up to 90 seconds before cleanup |
| 120 | Disconnect after 120 seconds of no RTP media | Very conservative; maximum tolerance for silent periods | Long ghost call duration before disconnect; wastes more capacity |
| 180+ | Extended timeout beyond typical recommendations | Special scenarios with very long expected silence (intercom systems, paging) | Not recommended for general VoIP; ghost calls linger too long |
VOS3000 SS_NOMEDIAHANGUPTIME Configuration:
Navigation: Operation Management > Softswitch Management
> Additional Settings > System Parameter
Parameter: SS_NOMEDIAHANGUPTIME
Type: Integer (seconds)
Default: 0 (disabled)
Recommended: 60 seconds for most wholesale deployments
IMPORTANT:
- Value of 0 disables the feature entirely
- Applies only to new calls after the parameter is saved
- Existing calls continue with the previously active setting
- Media Proxy mode MUST be enabled for this feature to function
Setting the Appropriate Timeout
Choosing the right value for SS_NOMEDIAHANGUPTIME requires balancing two competing concerns. A timeout that is too short risks disconnecting legitimate calls where one or both parties are silent for an extended period โ for example, during a hold, mute, or a natural pause in conversation. A timeout that is too long allows ghost calls to waste concurrent call capacity and inflate CDR durations before they are finally cleaned up.
The key insight is that RTP packets are normally sent continuously during a VoIP call, even when the parties are silent. This is because most codecs โ including G.711, G.729, and G.723 โ generate RTP packets containing silence or comfort noise data. Even when both parties are completely silent, RTP packets continue to flow at the codec’s packetization rate (typically every 20ms or 30ms). The only time RTP stops flowing on a legitimate call is when there is a genuine network or endpoint failure.
However, some codecs and configurations implement silence suppression (also called Voice Activity Detection or VAD), which stops sending RTP packets during silent periods. If your deployment uses VAD-enabled codecs, you must set SS_NOMEDIAHANGUPTIME high enough to accommodate the longest expected silence period. For most deployments without VAD, a 60-second timeout provides an excellent balance between rapid ghost call cleanup and tolerance for legitimate call scenarios.
No Media Hangup vs Session Timer: Critical Differences
VOS3000 provides two separate mechanisms for detecting and cleaning up dead calls: the no media hangup feature and the SIP session timer. Understanding the differences between these two mechanisms is essential for proper configuration and avoiding the common confusion between them.
| ๐ Aspect | ๐ป No Media Hangup | โฑ๏ธ Session Timer |
|---|---|---|
| Protocol layer | RTP media layer | SIP signaling layer |
| What it monitors | RTP packet reception โ whether media is flowing | SIP re-INVITE/UPDATE refresh โ whether signaling session is alive |
| Detection method | No RTP packets received for X seconds | SIP session refresh fails (re-INVITE timeout) |
| Trigger condition | Media path failure while SIP signaling may still be alive | SIP signaling path failure; both signaling and media are dead |
| Typical timeout | 30-120 seconds (configurable via SS_NOMEDIAHANGUPTIME) | 32 seconds default drop after session refresh failure |
| Parameter | SS_NOMEDIAHANGUPTIME | Session-Expires header and Min-SE in SIP messages |
| Catches ghost calls? | Yes โ detects calls with dead media but live signaling | No โ session timer refresh requires signaling to fail; ghost calls have live signaling |
| Media Proxy required? | Yes โ must proxy media to monitor RTP | No โ operates purely in SIP signaling layer |
| Best for | Detecting ghost calls where media dies but signaling survives | Detecting total signaling failure where both SIP and RTP are dead |
The critical takeaway is that the session timer alone cannot catch ghost calls. When a call becomes a ghost โ media is dead but SIP signaling is still alive โ the session timer refresh succeeds because the SIP path is functional. Only the no media hangup feature can detect this specific condition because it monitors the RTP stream independently of the SIP signaling state. For complete call cleanup, both mechanisms should be configured together. Learn more about the session timer in our VOS3000 session timer 32-second drop guide.
Media Proxy Mode Interaction with No Media Hangup
The VOS3000 no media hangup feature has a critical dependency on Media Proxy mode. Because the detection mechanism works by monitoring RTP packet reception at the media relay level, the media proxy must be active for each call that you want to monitor. If calls are established in direct media bypass mode โ where RTP flows directly between endpoints without passing through the VOS3000 server โ the no media hangup feature cannot detect ghost calls because the server never sees the RTP packets.
| ๐ง Media Mode | ๐ป No Media Hangup | ๐ RTP Visibility | โ ๏ธ Notes |
|---|---|---|---|
| Media Proxy (Relay) | โ Fully functional | All RTP packets pass through VOS3000; full monitoring capability | Recommended mode for ghost call detection |
| Media Bypass (Direct) | โ Not functional | RTP flows directly between endpoints; VOS3000 cannot monitor packets | Ghost calls will NOT be detected in bypass mode |
| Mixed Mode | โก Partially functional | Only proxied calls are monitored; bypassed calls are invisible | Inconsistent ghost call detection across your traffic |
To ensure complete ghost call detection, configure your VOS3000 system to use Media Proxy mode for all calls. This means setting the appropriate media relay configuration for your gateways and ensuring that calls are not falling through to direct media bypass. The tradeoff is slightly higher server resource consumption, as the media relay must process and forward every RTP packet. However, the benefit of automatic ghost call cleanup far outweighs the marginal increase in CPU and bandwidth usage for most deployments.
For guidance on configuring Media Proxy mode and optimizing server resources, see our VOS3000 RTP media guide and VOS3000 system parameters guide. For hands-on assistance, contact us on WhatsApp at +8801911119966.
Detecting Ghost Calls in CDR: Identifying the Patterns
Even with no media hangup configured, you should regularly audit your CDR records to identify ghost call patterns. Ghost calls leave distinctive signatures in CDR data that can be detected through analysis. Early detection of ghost call patterns helps you identify network issues, endpoint problems, and configuration gaps before they cause significant billing disputes.
| ๐ CDR Pattern | ๐ป Indicates | ๐ Typical Values | โ Action |
|---|---|---|---|
| Very long duration with zero billed amount | Ghost call that was eventually cleaned up by no media hangup | Duration: 60-300 seconds; Billed: $0.00 | Verify no media hangup is working; check if timeout is appropriate |
| Unusually long duration with near-zero billed amount | Ghost call with minimal media before timeout | Duration: hundreds of seconds; Billed: fractions of a cent | Reduce SS_NOMEDIAHANGUPTIME if too many calls affected |
| Multiple calls from same endpoint with identical long durations | Systematic endpoint or network issue causing repeated ghost calls | Duration: matches SS_NOMEDIAHANGUPTIME value consistently | Investigate the specific endpoint; check NAT, firewall, and network path |
| Calls that end exactly at the no media hangup timeout | No media hangup is actively cleaning up ghost calls | Duration: matches SS_NOMEDIAHANGUPTIME + initial media period | Feature is working correctly; investigate root cause of media loss |
| Disproportionate ACD (Average Call Duration) for specific routes | Route-level network issues causing ghost calls | ACD significantly higher than expected for the destination | Check the vendor/gateway for that route; test media path quality |
| Spike in concurrent call count without corresponding traffic increase | Accumulating ghost calls during a network event | Concurrent calls near license limit; CDR shows many long-duration calls | Verify no media hangup is enabled; check Media Proxy mode is active |
Using Current Call Monitor for Real-Time Detection
VOS3000 provides a real-time Current Call monitor that shows all active calls on the system. During a network event, you can use the Current Call monitor to identify ghost calls in real time:
- Open Current Call: Navigate to Operation Management > Call Management > Current Call
- Sort by duration: Click the duration column to sort calls from longest to shortest
- Identify anomalies: Calls with unusually long durations, especially from the same endpoint or gateway, are likely ghost calls
- Check media status: If available, observe whether the media relay shows active RTP for each call
- Manual disconnect: You can manually disconnect suspected ghost calls from the Current Call interface
Regular monitoring of the Current Call screen helps you identify ghost call patterns early and confirm that your SS_NOMEDIAHANGUPTIME configuration is working effectively.
Recommended Timeout by Call Type – VOS3000 no media hangup
Different call scenarios have different tolerance levels for silence periods, and the SS_NOMEDIAHANGUPTIME value should be set according to the most sensitive call type in your deployment. The following table provides recommended timeout values based on common VoIP call types and their expected media behavior.
| ๐ Call Type | โฑ๏ธ Recommended Timeout | ๐ก Reasoning | โ ๏ธ Risk of Too Short |
|---|---|---|---|
| Wholesale termination | 30-60 seconds | High call volume; every slot matters; minimal silence expected | Brief holds during IVR transfer could be disconnected |
| Retail VoIP | 60-90 seconds | End users may mute or hold; need more tolerance for natural silence | Users on hold may be disconnected unexpectedly |
| Call center / IVR | 90-120 seconds | IVR menus and queue hold times create extended silence periods | Callers in queue may be dropped while waiting for agent |
| SIP trunking | 60 seconds | PBX trunk connections; moderate silence tolerance needed | PBX hold music should generate RTP; silence may indicate real problem |
| VAD-enabled endpoints | 120-180 seconds | Voice Activity Detection suppresses RTP during silence; needs longer timeout | Normal silent conversation gaps will trigger disconnect |
| Emergency services | 120+ seconds (or disable) | Never disconnect emergency calls; silence may be critical situation | Disconnecting emergency calls is dangerous and may violate regulations |
If your VOS3000 deployment handles multiple call types, set SS_NOMEDIAHANGUPTIME to accommodate the most sensitive call type that requires the longest silence tolerance. Alternatively, consider separating different call types onto different VOS3000 instances or prefixes with different configurations. For guidance on optimizing timeout settings for your specific traffic mix, contact us on WhatsApp at +8801911119966.
Use Case: Preventing Billing Disputes from Ghost Calls
One of the most impactful applications of the VOS3000 no media hangup feature is preventing billing disputes. Consider a scenario common in wholesale VoIP: a carrier routes 10,000 calls per day through a vendor gateway. During a 2-hour network instability event, 200 calls lose their RTP media path but remain connected in SIP signaling. Without no media hangup, these 200 ghost calls persist until the endpoints time out or the session expires โ potentially lasting 4-6 hours each.
The CDR records show 200 calls with durations of 4-6 hours each. When the billing system calculates charges based on these CDR durations, the customer is billed for 800-1200 hours of call time that had no actual voice communication. When the customer reviews their invoice and CDR records, they find hundreds of calls with extremely long durations and dispute the entire batch of charges. The dispute resolution process consumes significant staff time, and the carrier often has to issue credits to maintain the business relationship.
With VOS3000 no media hangup configured with SS_NOMEDIAHANGUPTIME set to 60 seconds, each ghost call is detected and terminated within 60 seconds of media loss. The 200 ghost calls generate CDR records showing durations of approximately 60 seconds instead of 4-6 hours. The total billed time is reduced from 800-1200 hours to approximately 3.3 hours, and the customer’s CDR shows reasonable call durations that match actual usage. Billing disputes are minimized, and the carrier’s revenue integrity is maintained.
For a complete understanding of VOS3000 billing and how CDR records are generated, see our VOS3000 billing system guide.
Use Case: Freeing Up Concurrent Call Capacity During Network Issues
Concurrent call capacity is a finite and valuable resource in any VOS3000 deployment. Your VOS3000 license determines the maximum number of simultaneous calls the system can handle, and every ghost call consumes one of these precious slots. During network instability events, ghost calls can accumulate rapidly, potentially exhausting your concurrent call capacity and blocking legitimate traffic.
Consider a VOS3000 system licensed for 2,000 concurrent calls during normal operation. The system typically handles 1,500-1,800 concurrent calls during peak hours, leaving 200-500 slots of headroom. A network event causes media loss on 500 calls, but SIP signaling survives on 400 of them. Without no media hangup, those 400 ghost calls remain connected indefinitely, reducing available capacity to 1,600 slots. When peak hour traffic arrives, the system hits the 2,000-call license limit with 400 ghost calls consuming capacity, and legitimate calls start failing with 503 Service Unavailable.
With VOS3000 no media hangup enabled, those 400 ghost calls are automatically terminated within 60 seconds of media loss. The 400 call slots are immediately freed up and available for legitimate traffic. The system maintains its full capacity for real calls, and the network event passes without any impact on call completion rates. This Smart automatic cleanup ensures that your concurrent call capacity is always available for genuine traffic, not wasted on zombie sessions.
Troubleshooting: Legitimate Calls Being Disconnected
The most common problem encountered with VOS3000 no media hangup is legitimate calls being incorrectly disconnected. This happens when the SS_NOMEDIAHANGUPTIME value is set too low for the actual silence patterns in your call traffic. When legitimate calls are disconnected, users experience unexpected call drops, and the CDR shows the disconnect reason as “no media” rather than a normal call termination.
Symptoms of Incorrect Disconnection
- Users report unexpected call drops: Callers complain that calls are disconnected during normal conversation, especially during pauses or hold periods
- CDR shows no media disconnect code: The CDR disconnect reason indicates no media timeout rather than a normal BYE from an endpoint
- Drops correlate with silence periods: Call drops tend to happen during IVR menus, hold periods, or natural conversation pauses
- Issue affects specific call types: Only certain routes or endpoints are affected, typically those with VAD enabled or those that generate silence during normal operation
Resolving Incorrect Disconnection
- Increase SS_NOMEDIAHANGUPTIME: The most direct solution is to increase the timeout value. If calls are being disconnected at 30 seconds, try 60 seconds. If 60 seconds is too aggressive, try 90 seconds
- Check for VAD-enabled endpoints: If any endpoints use Voice Activity Detection, RTP stops during silence. Either disable VAD on those endpoints or increase the timeout to accommodate silence periods
- Verify Media Proxy is correctly configured: In rare cases, Media Proxy misconfiguration can cause the server to miss RTP packets that are actually flowing. Verify that the media relay is processing packets correctly using packet capture
- Analyze specific affected calls: Use SIP trace and RTP capture to examine the calls being disconnected. Confirm that RTP truly stops before the timeout, or whether the monitoring is incorrectly reporting no media
- Consider per-route configuration: If only certain routes or endpoints are affected, consider whether you can isolate those calls and apply different settings
For help diagnosing and resolving no media hangup disconnection issues, see our VOS3000 audio troubleshooting guide or contact us on WhatsApp at +8801911119966.
Configuration and Testing Checklist (VOS3000 no media hangup)
Use this checklist to ensure your VOS3000 no media hangup configuration is complete and working correctly before relying on it in production. Each step should be verified and documented.
| โ Step | ๐ Action | ๐ Details | โ ๏ธ Important |
|---|---|---|---|
| 1 | Verify Media Proxy mode is active | Check that calls are being proxied, not bypassed, in the media relay configuration | No media hangup does NOT work in bypass mode |
| 2 | Set SS_NOMEDIAHANGUPTIME | Navigate to Softswitch Management > System Parameter and set the timeout value in seconds | Start with 60 seconds; adjust based on your call types |
| 3 | Test with a legitimate call | Place a normal test call and verify it stays connected during normal conversation | Ensure the timeout does not affect normal calls |
| 4 | Test ghost call detection | Simulate a ghost call by establishing a call and then blocking RTP on one endpoint | Call should disconnect within SS_NOMEDIAHANGUPTIME seconds of RTP loss |
| 5 | Verify CDR records | Check that CDR shows correct disconnect reason for the auto-disconnected call | CDR should show no media timeout as the disconnect cause |
| 6 | Test with hold/mute scenario | Place a call, put one side on hold, and verify the call stays connected | Hold music should generate RTP; if not, timeout may trigger |
| 7 | Monitor Current Call during peak | Watch the Current Call screen during peak hours for ghost call accumulation | Concurrent call count should not spike abnormally during network events |
| 8 | Audit CDR for ghost call patterns | After 24 hours, review CDR for calls matching ghost call patterns (long duration, zero billing) | Ghost call patterns should be eliminated or significantly reduced |
| 9 | Configure session timer as backup | Ensure SIP session timer is also configured for total signaling failure scenarios | No media hangup + session timer = complete call cleanup coverage |
| 10 | Document configuration | Record SS_NOMEDIAHANGUPTIME value, Media Proxy mode, and session timer settings | Essential for future troubleshooting and configuration audits |
VOS3000 No Media Hangup Configuration Summary: Step 1: Verify Media Proxy mode is active for all call paths Step 2: Set SS_NOMEDIAHANGUPTIME = 60 (recommended starting value) Step 3: Save system parameter changes Step 4: Test with legitimate call โ verify no false disconnects Step 5: Simulate ghost call โ verify auto-disconnect works Step 6: Check CDR records for correct disconnect reason Step 7: Monitor Current Call during peak hours Step 8: Audit CDR after 24 hours for ghost call patterns Step 9: Configure SIP session timer as additional safety net Step 10: Document all settings for future reference Both no media hangup AND session timer should be configured for complete protection against dead calls.
FAQ: VOS3000 No Media Hangup
1. What is no media hangup in VOS3000?
No media hangup is a VOS3000 feature that automatically disconnects calls when the RTP media stream stops flowing. It monitors RTP packet reception for each active call through the media relay. When no RTP packets are received for the duration specified by the SS_NOMEDIAHANGUPTIME parameter, VOS3000 sends a SIP BYE to terminate the call. This Smart mechanism prevents ghost calls โ calls that remain connected in SIP signaling but have no active voice media โ from wasting concurrent call capacity and corrupting CDR billing records. The feature is documented in VOS3000 Manual Section 4.3.5.2 and requires Media Proxy mode to be active for RTP monitoring.
2. What is the SS_NOMEDIAHANGUPTIME parameter?
SS_NOMEDIAHANGUPTIME is a VOS3000 softswitch system parameter that defines the number of seconds the system waits without receiving any RTP packets before automatically disconnecting a call. The parameter is configured in Operation Management > Softswitch Management > Additional Settings > System Parameter. A value of 0 disables the feature entirely. Common production values range from 30 to 120 seconds, with 60 seconds being the recommended starting point for most wholesale VoIP deployments. The parameter only takes effect for new calls after it is saved; existing calls continue with the previously active value.
3. How do ghost calls affect VoIP billing?
Ghost calls have a direct and damaging impact on VoIP billing accuracy. When a call becomes a ghost โ SIP signaling remains connected but RTP media stops โ the CDR timer continues to run. The CDR records the full duration from call answer to eventual disconnect, including potentially hours of dead air time. The billing system calculates charges based on these inflated CDR durations, resulting in customers being billed for time when no voice communication was actually happening.
This leads to billing disputes, credit requests, and damaged business relationships. The VOS3000 no media hangup feature addresses this by automatically terminating ghost calls within the configured timeout, keeping CDR durations accurate and proportional to actual media activity. For more on billing accuracy, see our VOS3000 billing system guide.
4. What is the difference between no media hangup and session timer?
No media hangup and the SIP session timer are two distinct call cleanup mechanisms in VOS3000 that operate at different protocol layers and detect different failure conditions. No media hangup operates at the RTP media layer โ it monitors whether voice packets are flowing and disconnects calls when media stops. The session timer operates at the SIP signaling layer โ it uses periodic SIP re-INVITE or UPDATE messages to verify that the SIP signaling path is alive and disconnects calls when the session refresh fails. The critical difference is that ghost calls typically have live SIP signaling but dead RTP media.
The session timer cannot detect ghost calls because the SIP refresh succeeds, while no media hangup can detect them because it monitors the media stream independently. Both mechanisms should be configured together for complete call cleanup coverage.
5. Why are legitimate calls being disconnected by no media hangup?
Legitimate calls are typically disconnected by the no media hangup feature when the SS_NOMEDIAHANGUPTIME value is set too short for the actual silence patterns in your call traffic. The most common cause is endpoints using Voice Activity Detection (VAD), which stops sending RTP packets during silent periods. If VAD is enabled and a caller pauses for longer than SS_NOMEDIAHANGUPTIME seconds, the system interprets the silence as a dead call and disconnects it.
Other causes include long IVR menu pauses, extended hold times without hold music generating RTP, and network jitter causing temporary RTP gaps. The solution is to increase SS_NOMEDIAHANGUPTIME to a value that accommodates the longest expected legitimate silence period, disable VAD on endpoints, or ensure that hold music and IVR prompts generate continuous RTP output.
6. How do I detect ghost calls in CDR records?
Ghost calls leave distinctive patterns in CDR records that can be identified through analysis. The most obvious indicator is a call with an unusually long duration but a zero or near-zero billed amount โ this suggests the call had no actual media flowing. Other patterns include: multiple calls from the same endpoint with identical durations matching the SS_NOMEDIAHANGUPTIME value; calls that end exactly at the no media hangup timeout plus the initial media period; and disproportionate Average Call Duration (ACD) for specific routes compared to expected values. To detect ghost calls systematically, sort your CDR by duration in descending order and review the top results.
Look for calls that are significantly longer than the typical ACD for their destination, especially if they cluster around specific endpoints, gateways, or time periods. For monitoring best practices, see our VOS3000 system parameters guide.
7. Does no media hangup work with media bypass mode in VOS3000?
No, the VOS3000 no media hangup feature does not work when calls are in media bypass (direct) mode. The feature relies on the media relay component to monitor RTP packet reception for each active call. In bypass mode, RTP media flows directly between the two endpoints without passing through the VOS3000 server, so the system has no visibility into whether packets are being exchanged. Without access to the RTP stream, the no media hangup timer cannot detect when media stops flowing.
For this reason, you must configure Media Proxy (relay) mode on your VOS3000 gateways and trunks if you want ghost call detection. In a mixed-mode deployment where some calls use proxy and others use bypass, only the proxied calls benefit from no media hangup protection, while bypassed calls remain vulnerable to ghost call accumulation.
Conclusion – VOS3000 no media hangup
Ghost calls are a persistent threat to VoIP operations, silently consuming concurrent call capacity, inflating CDR durations, and generating billing disputes that erode customer confidence. The VOS3000 no media hangup feature, configured through the SS_NOMEDIAHANGUPTIME system parameter, provides a Smart and effective solution by automatically detecting and terminating calls when RTP media stops flowing.
Key takeaways from this guide:
- Ghost calls occur when SIP signaling survives but RTP media dies โ they are invisible to both parties and persist until explicitly terminated
- SS_NOMEDIAHANGUPTIME controls the auto-disconnect timeout โ set it to 60 seconds for most wholesale deployments; 0 disables the feature
- Media Proxy mode is required โ the feature only works when VOS3000 is proxying RTP media, not in bypass mode
- No media hangup and session timer serve different purposes โ configure both for complete call cleanup coverage
- Choose your timeout carefully โ too short disconnects legitimate calls; too long wastes capacity on ghost calls
- Monitor CDR patterns regularly โ ghost call signatures in CDR data reveal network issues before they cause major problems
By implementing VOS3000 no media hangup with the appropriate timeout for your traffic patterns, you can eliminate ghost calls, protect billing accuracy, and ensure that your concurrent call capacity is always available for genuine voice traffic. For professional VOS3000 configuration and support, visit VOS3000 downloads or contact us on WhatsApp at +8801911119966.
๐ Need Professional VOS3000 Setup Support?
For professional VOS3000 installations and deployment, VOS3000 Server Rental Solution:
๐ฑ WhatsApp: +8801911119966
๐ Website: www.vos3000.com
๐ Blog: multahost.com/blog
๐ฅ Downloads: VOS3000 Downloads
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