> Source: [sk182808](https://support.checkpoint.com/results/sk/sk182808)

# sk182808 - SIP traffic is dropped for "Malformed SIP packet" with reason "Invalid SDP header" on SDP packet type 180 (Ringing)

| Property | Value |
|----------|-------|
| Solution ID | sk182808 |
| Date Created | 2024-11-18 |
| Last Modified | 2024-11-19 |
| Technical Level | Advanced |
| Products | Security Gateway |
| Versions | R81.20, R81.10 (EOS) |

## Symptoms

- * SIP traffic is dropping with the a log for "Malformed SIP packet" with reason "Invalid SDP header".
* The dropped packet is of type 180 (Ringing) in the SIP protocol.
* Kernel debug shows these errors: `@;2212169956; 4May2022 13:53:59.018056;[vs_10];[tid_0];[fw4_0];sip_save_sdp_invite: Failed - unexcpected pkt_type=180;` `@;2212169956; 4May2022 13:53:59.018058;[vs_10];[tid_0];[fw4_0];sip_handle_sdp: failed to save SDP. dropping;`
* Disabling the protection that inspects the content-length header in SIP messages with SDP resolves the issue:
  1. To disable the protection, on the active member, run: `# fw ctl set int sip_check_content_len 0`
  2. To enable it back run: `#fw ctl set int sip_check_content_len 1`

## Solution

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