Credential Stuffing<\/td> Leaked username\/password combos from other breaches<\/td> SIP accounts with reused passwords<\/td> \ud83d\udd34 Critical<\/td> \u2705 Yes \u2014 limits attempt count<\/td><\/tr> Registration Flood (DoS)<\/td> Massive volume of registration requests to overwhelm server<\/td> Server CPU and memory resources<\/td> \ud83d\udfe1 Medium<\/td> \u26a0\ufe0f Partial \u2014 reduces load but not designed for DDoS<\/td><\/tr> Man-in-the-Middle<\/td> Intercepting SIP traffic to capture authentication hashes<\/td> SIP digest authentication hashes<\/td> \ud83d\udfe1 Medium<\/td> \u274c No \u2014 requires TLS\/SRTP instead<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\nVOS3000 Authentication Suspend System Parameters Explained<\/h2>\n\n\n\n The VOS3000 authentication suspend<\/strong> feature is controlled by three system parameters accessible through the VOS3000 client interface. These parameters are located under Softswitch Management > Additional Settings > System Parameter<\/strong>, and they work together to define the lockout behavior. Let us examine each parameter in detail.<\/p>\n\n\n\nSS_ENDPOINTREGISTERSUSPEND \u2014 Master Switch<\/h3>\n\n\n\n This is the enable\/disable toggle<\/strong> for the entire authentication suspend feature. When set to 1<\/strong>, the feature is active and the system will monitor failed registration attempts and enforce suspension. When set to 0<\/strong>, the feature is completely disabled, and all registration attempts are processed without any lockout protection.<\/p>\n\n\n\nDefault value:<\/strong> 0 (disabled) \u2014 This means you must explicitly enable<\/strong> authentication suspend on a new VOS3000 installation. Running VOS3000 without this feature enabled is a significant security risk.<\/p>\n\n\n\nSS_ENDPOINTREGISTERRETRY \u2014 Attempt Threshold<\/h3>\n\n\n\n This parameter defines the maximum number of consecutive failed registration attempts<\/strong> allowed before the system triggers a suspension. Each time an endpoint fails to authenticate, the counter increments. When the counter reaches the configured value, the registration is suspended.<\/p>\n\n\n\nDefault value:<\/strong> 6 \u2014 After six consecutive failed registration attempts, the endpoint is suspended. A successful registration resets the counter back to zero.<\/p>\n\n\n\nSS_ENDPOINTREGISTERSUSPENDTIME \u2014 Lockout Duration<\/h3>\n\n\n\n This parameter specifies how long the suspension lasts<\/strong>, measured in seconds. During the suspension period, any registration attempt from the suspended endpoint is immediately rejected without processing through the authentication pipeline. This saves server resources and prevents the attacker from making any progress.<\/p>\n\n\n\nDefault value:<\/strong> 180 seconds (3 minutes) \u2014 After the suspension expires, the endpoint can attempt to register again, and the failed attempt counter resets.<\/p>\n\n\n\n\ud83d\udccb Parameter Name<\/th> \u2699\ufe0f Function<\/th> \ud83d\udcdd Default Value<\/th> \ud83c\udfaf Valid Range<\/th> \ud83d\udca1 Recommendation<\/th><\/tr> SS_ENDPOINTREGISTERSUSPEND<\/strong><\/td>Enable\/disable authentication suspend<\/td> 0 (disabled)<\/td> 0 or 1<\/td> 1 (always enable)<\/td><\/tr> SS_ENDPOINTREGISTERRETRY<\/strong><\/td>Max failed attempts before suspend<\/td> 6<\/td> 1\u2013100<\/td> 3\u20135 (strict) or 6 (balanced)<\/td><\/tr> SS_ENDPOINTREGISTERSUSPENDTIME<\/strong><\/td>Suspension duration in seconds<\/td> 180<\/td> 60\u201386400<\/td> 300\u20133600 depending on threat level<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\nHow the VOS3000 Authentication Suspend Mechanism Works<\/h2>\n\n\n\n Understanding the internal operation of the VOS3000 authentication suspend<\/strong> mechanism helps you configure it optimally. Here is the step-by-step flow of how the lockout process works:<\/p>\n\n\n\n\nSIP Registration Request Arrives<\/strong> \u2014 An endpoint sends a REGISTER request to the VOS3000 softswitch with a SIP extension number and authentication credentials.<\/li>\n\n\n\nAuthentication Challenge Issued<\/strong> \u2014 VOS3000 responds with a 401 Unauthorized, including a nonce for digest authentication.<\/li>\n\n\n\nCredential Verification<\/strong> \u2014 The endpoint responds with the computed digest hash. VOS3000 verifies the credentials against its database.<\/li>\n\n\n\nFailed Attempt Counter Incremented<\/strong> \u2014 If authentication fails, the SS_ENDPOINTREGISTERRETRY<\/strong> counter for that endpoint increments by one.<\/li>\n\n\n\nThreshold Check<\/strong> \u2014 The system compares the current failed attempt count against the SS_ENDPOINTREGISTERRETRY<\/strong> value. If the count is below the threshold, the endpoint is allowed to try again.<\/li>\n\n\n\nSuspension Triggered<\/strong> \u2014 Once the failed attempt count equals or exceeds the threshold, the system activates the suspension. The endpoint is locked out for the duration specified by SS_ENDPOINTREGISTERSUSPENDTIME<\/strong>.<\/li>\n\n\n\nRegistration Rejected During Suspension<\/strong> \u2014 Any subsequent registration attempt from the suspended endpoint is immediately rejected with a 403 Forbidden<\/strong> response, without further authentication processing.<\/li>\n\n\n\nSuspension Expires<\/strong> \u2014 After the timer expires, the endpoint can register again, and the failed attempt counter resets to zero.<\/li>\n<\/ol>\n\n\n\nIt is critical to note that a successful registration resets the counter<\/strong>. This means if a legitimate user accidentally mistypes their password a few times but then enters it correctly before the threshold is reached, the counter resets and no suspension occurs. This design prevents false positives for users who occasionally make typing errors.<\/p>\n\n\n\nConfiguring Authentication Suspend in VOS3000<\/h2>\n\n\n\n Configuring the VOS3000 authentication suspend<\/strong> feature requires access to the VOS3000 client (the Java-based management GUI). Follow these steps to enable and configure the three system parameters:<\/p>\n\n\n\nStep 1: Access System Parameters<\/h3>\n\n\n\n Log in to your VOS3000 client and navigate to:<\/p>\n\n\n\n
Softswitch Management > Additional Settings > System Parameter\n<\/pre>\n\n\n\nIn the system parameter list, search for each of the three authentication suspend parameters. They are listed alphabetically among all VOS3000 system parameters.<\/p>\n\n\n\n
Step 2: Enable Authentication Suspend<\/h3>\n\n\n\n Locate SS_ENDPOINTREGISTERSUSPEND<\/strong> and set its value to 1<\/strong>. This activates the feature. If this parameter remains at the default value of 0, no suspension will ever occur regardless of the other parameter settings.<\/p>\n\n\n\nParameter: SS_ENDPOINTREGISTERSUSPEND\nValue: 1\nDescription: Enable authentication suspend after failed registration attempts\n<\/pre>\n\n\n\nStep 3: Set the Retry Threshold<\/h3>\n\n\n\n Locate SS_ENDPOINTREGISTERRETRY<\/strong> and set the number of failed attempts that will trigger a suspension. The default value of 6 is reasonable for most environments, but you may want to adjust it based on your security posture.<\/p>\n\n\n\nParameter: SS_ENDPOINTREGISTERRETRY\nValue: 5\nDescription: Number of consecutive failed registrations before suspend\n<\/pre>\n\n\n\nStep 4: Set the Suspension Duration<\/h3>\n\n\n\n Locate SS_ENDPOINTREGISTERSUSPENDTIME<\/strong> and set the lockout duration in seconds. Consider your threat environment and user behavior when choosing this value.<\/p>\n\n\n\nParameter: SS_ENDPOINTREGISTERSUSPENDTIME\nValue: 600\nDescription: Duration in seconds to suspend registration (600 = 10 minutes)\n<\/pre>\n\n\n\nStep 5: Apply and Verify<\/h3>\n\n\n\n After modifying the parameters, apply the changes in the VOS3000 client. The changes typically take effect immediately for new registration attempts. You can verify the configuration by intentionally failing registration attempts on a test extension and confirming that it gets suspended after the configured number of retries.<\/p>\n\n\n\n
For a complete walkthrough of all VOS3000 system parameters, refer to our VOS3000 system parameters guide<\/a>.<\/p>\n\n\n\nSS_ENDPOINTREGISTERRETRY Value Recommendations<\/h2>\n\n\n\n Choosing the right value for SS_ENDPOINTREGISTERRETRY<\/strong> is a balance between security and usability. Setting it too low may lock out legitimate users who mistype their passwords, while setting it too high gives attackers more chances to guess correctly.<\/p>\n\n\n\n\u2699\ufe0f Retry Value<\/th> \ud83d\udcdd Security Level<\/th> \ud83c\udfaf Best For<\/th> \ud83d\udca1 Trade-off<\/th><\/tr> 3<\/td> \ud83d\udd34 Maximum<\/td> High-security environments, servers under active attack<\/td> Higher risk of locking legitimate users with typos<\/td><\/tr> 5<\/td> \ud83d\udfe0 High<\/td> Production servers with moderate attack surface<\/td> Good balance \u2014 allows a few typos before lockout<\/td><\/tr> 6 (default)<\/td> \ud83d\udfe1 Moderate-High<\/td> Standard deployments, most common choice<\/td> VOS3000 default \u2014 works well for typical environments<\/td><\/tr> 10<\/td> \ud83d\udfe2 Moderate<\/td> Environments with less-technical users who mistype often<\/td> More attempts allowed \u2014 slightly higher attack window<\/td><\/tr> 20+<\/td> \ud83d\udd35 Low<\/td> Not recommended \u2014 too many attempts before lockout<\/td> Attackers get significant opportunity to brute-force<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\nFor most production environments, we recommend setting SS_ENDPOINTREGISTERRETRY to 5<\/strong>. This provides strong protection while giving legitimate users enough attempts to correct typos. If your server is currently under active brute-force attack, consider temporarily lowering this to 3. Need help securing your VOS3000 server urgently? Contact us on WhatsApp at +8801911119966<\/strong> for immediate assistance.<\/p>\n\n\n\nSS_ENDPOINTREGISTERSUSPENDTIME Value Recommendations<\/h2>\n\n\n\n The suspension duration determines how long an attacker must wait before trying again. Longer durations provide better protection but may inconvenience legitimate users who trigger a lockout. Here are our recommendations based on different scenarios:<\/p>\n\n\n\n\u23f1\ufe0f Duration (Seconds)<\/th> \u23f1\ufe0f Duration (Minutes)<\/th> \ud83d\udcdd Security Level<\/th> \ud83c\udfaf Best For<\/th><\/tr> 60<\/td> 1 minute<\/td> \ud83d\udd35 Low \u2014 attacker retries quickly<\/td> Testing environments only<\/td><\/tr> 180 (default)<\/td> 3 minutes<\/td> \ud83d\udfe1 Moderate \u2014 default value<\/td> Basic protection, minimal user disruption<\/td><\/tr> 300<\/td> 5 minutes<\/td> \ud83d\udfe0 High \u2014 good balance<\/td> Standard production servers<\/td><\/tr> 600<\/td> 10 minutes<\/td> \ud83d\udd34 Very High<\/td> Servers under active attack<\/td><\/tr> 1800<\/td> 30 minutes<\/td> \ud83d\udd34 Maximum<\/td> Critical infrastructure, severe attack scenarios<\/td><\/tr> 3600<\/td> 60 minutes<\/td> \ud83d\udd34 Extreme<\/td> Maximum security \u2014 may inconvenience locked users<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\nFor production VOS3000 servers, we recommend setting SS_ENDPOINTREGISTERSUSPENDTIME to 600<\/strong> (10 minutes). This provides a substantial deterrent against brute-force attacks \u2014 an attacker limited to 5 attempts every 10 minutes would need over 22 years<\/strong> to try 6 million passwords. Meanwhile, a legitimate user who triggers a lockout only needs to wait 10 minutes before trying again. For expert guidance on configuring these values for your specific deployment, reach out on WhatsApp at +8801911119966<\/strong>.<\/p>\n\n\n\nVOS3000 Authentication Suspend vs Dynamic Blacklist<\/h2>\n\n\n\n VOS3000 offers multiple security layers, and administrators sometimes confuse authentication suspend<\/strong> with the dynamic blacklist<\/strong> feature. While both protect against malicious activity, they operate differently and serve distinct purposes. Understanding the difference is crucial for building an effective defense-in-depth strategy.<\/p>\n\n\n\n