ConnectivityProblems » History » Version 18
Adrian Georgescu, 07/21/2013 10:29 PM
| 1 | 1 | Adrian Georgescu | h1. Connectivity Problems |
|---|---|---|---|
| 2 | |||
| 3 | 15 | Adrian Georgescu | Real-time communication using SIP protocol between end-points may fail. Real-time communications, regardless of protocol used (XMPP is no different), is a complex topic, for each session several IP addresses, port and protocols combinations are used in both directions. What are the possible reasons for such failures? Here is a checklist that can help eliminate possible causes: |
| 4 | 1 | Adrian Georgescu | |
| 5 | 7 | Adrian Georgescu | h2. Software version |
| 6 | |||
| 7 | 18 | Adrian Georgescu | * Upgrade to the latest version of your application, very often a problem may have already been solved even if the changeling does not explicitly list it. Unfortunately, there is also a risk of breaking existing functionality when installing a new version that contains a bug. |
| 8 | 7 | Adrian Georgescu | |
| 9 | 1 | Adrian Georgescu | h2. Local Computer |
| 10 | |||
| 11 | 5 | Adrian Georgescu | * Firewall software installed. Check if no software blocks access to the ports used by your application or enable the use of the proper ports in the firewall configuration. |
| 12 | 1 | Adrian Georgescu | |
| 13 | 2 | Adrian Georgescu | h2. Internet Router |
| 14 | 1 | Adrian Georgescu | |
| 15 | 11 | Adrian Georgescu | * SIP ALG enabled. Your router re-writes the content of your SIP packets. Check of the router has any so called SIP support and "disabled it":http://www.voip-info.org/wiki/view/Routers+SIP+ALG |
| 16 | 5 | Adrian Georgescu | * Firewall enabled. Check if no software blocks access to the ports used by your application or enable the use of the proper ports in the firewall configuration. |
| 17 | 1 | Adrian Georgescu | |
| 18 | 3 | Adrian Georgescu | h2. Internet Provider |
| 19 | 1 | Adrian Georgescu | |
| 20 | * Policy that blocks either SIP signalling or RTP media. You can try use another SIP service provider that provides access over TCP or TLS instead of UDP or is using custom ports. Otherwise use another ISP. |
||
| 21 | 12 | Adrian Georgescu | * Provider does not allow the use of ICE for NAT traversal and forces a media relay instead. Turn of ICE in the client. |
| 22 | 1 | Adrian Georgescu | |
| 23 | 3 | Adrian Georgescu | h2. SIP Service Provider |
| 24 | 1 | Adrian Georgescu | |
| 25 | 13 | Adrian Georgescu | * Provider requires use of STUN protocol so that the SIP devices uses a public IP address in the Contact header. This is wrong and unreliable, such behaviour is explicitly discouraged by the "standards":http://projects.ag-projects.com/projects/blinkc/wiki/MostEncounteredProblems#SIP-Provider-requires-STUN |
| 26 | * Provider does does not support certain audio or video codecs. Instead of rejecting such sessions with an appropriate code, they simply won't answer. |