> Source: [sk116739](https://support.checkpoint.com/results/sk/sk116739)

# sk116739 - SIP calls receive a fast busy signal

| Property | Value |
|----------|-------|
| Solution ID | sk116739 |
| Date Created | 2017-04-06 |
| Last Modified | 2019-06-10 |
| Technical Level | Advanced |
| Products | Security Gateway |
| Versions | R82.10, R82, R81.20 |

## Symptoms

- * SIP calls receive a fast busy signal, since SIP session progress packets are not being NATed.  

* sipdebug kernel debug shows:

  ```
  
  DATE TIME.PID... sip_ws_parser: Start parsing the SIP packet;
  DATE TIME.PID... ws_parse_request_line: [WARNING]: Unknown method found in request;
  DATE TIME.PID... ws_parse_request_line: [WARNING]: method SIP/2.0 is unknown to parser;
  DATE TIME.PID... ws_parse_proto_version: [WARNING]: request parsing failed due to a malformed HTTP protocol name:;
  DATE TIME.PID... ws_parse_proto_version: [WARNING]:   expected: 'H', received: 'S';
  DATE TIME.PID... ws_parse_proto_version: [WARNING]: request parsing failed due to a malformed HTTP protocol name:;
  DATE TIME.PID... ws_parse_proto_version: [WARNING]:   expected: 'H', received: 'e';
  DATE TIME.PID... ws_parse_proto_version: [WARNING]: request parsing failed due to a malformed HTTP protocol name:;
  DATE TIME.PID... ws_parse_proto_version: [WARNING]:   expected: 'H', received: 's';
  DATE TIME.PID... ws_parse_proto_version: [WARNING]: request parsing failed due to a malformed HTTP protocol name:;
  DATE TIME.PID... ws_parse_proto_version: [WARNING]:   expected: 'H', received: 'i';
  DATE TIME.PID... ws_parse_proto_version: [WARNING]: request parsing failed due to a malformed HTTP protocol name:;
  DATE TIME.PID... ws_parse_proto_version: [WARNING]:   expected: 'H', received: 'o';
  DATE TIME.PID... ws_parse_proto_version: [WARNING]: request parsing failed due to a malformed HTTP protocol name:;
  DATE TIME.PID... ws_parse_proto_version: [WARNING]:   expected: 'H', received: 'n';
  DATE TIME.PID... ws_parse_request_line: [WARNING]: request parsing failed due to a malformed HTTP version;
  DATE TIME.PID... sip_ws_parser: Parsing failed!;
  DATE TIME.PID... sip_run_parser: Generic parsing failed
  ```

## Cause

Security gateway cannot parse these messages and as a result cannot translate the content, that is why the busy signal is received

## Solution

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