# SIP/2.0 414 Request-URI Too Long on INVITE

- **ID:** `communication/sip-request-uri-too-long`
- **Domain:** communication
- **Category:** protocol_error
- **Error Code:** `414`
- **Verification:** ai_generated
- **Fix Rate:** 78%

## Root Cause

SIP INVITE request URI exceeds the maximum allowed length (typically 2048 bytes) configured in the SIP proxy or registrar, often due to long phone numbers, excessive URI parameters, or malformed headers.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| Asterisk 18.15.0 | active | — | — |
| FreeSWITCH 1.10.9 | active | — | — |
| Kamailio 5.6.0 | active | — | — |
| OpenSIPS 3.4.0 | active | — | — |
| Cisco Unified CM 14.0 | active | — | — |

## Workarounds

1. **Increase the max URI length in Kamailio: edit kamailio.cfg, add 'modparam("sl", "max_uri_len", 4096)' and reload configuration.** (80% success)
   ```
   Increase the max URI length in Kamailio: edit kamailio.cfg, add 'modparam("sl", "max_uri_len", 4096)' and reload configuration.
   ```
2. **Shorten the SIP URI by removing unnecessary URI parameters (e.g., user=phone, transport=tcp) in the dial plan or using a URI normalization function.** (75% success)
   ```
   Shorten the SIP URI by removing unnecessary URI parameters (e.g., user=phone, transport=tcp) in the dial plan or using a URI normalization function.
   ```

## Dead Ends

- **Disable SIP URI length check entirely in config** — Disabling the length check exposes the server to denial-of-service attacks via extremely long URIs and may violate SIP standards. (95% fail)
- **Increase TCP buffer size on the SIP proxy** — TCP buffer size does not affect the SIP URI length limit, which is enforced at the application layer by the SIP stack. (90% fail)
- **Restart the SIP service to clear the error** — Restarting only resets the connection state; the URI length violation reoccurs on the next INVITE with the same URI. (85% fail)