[Linphone-developers] Questions regarding linphone ICE support

[Robbert Bakker]

Good evening to all Linphone developers,

 

# Linphone P2P streaming

 

We have selected Linphone as a candidate for the video streaming functionality in a remote social communication application. This guidance program is used within a Wifi network, within one location where clients are living.

 

The guidance application is implemented as an app on the Android OS. Everyone will have its own tablet with their respective app suited for their role. So there will be multiple devices within the same internal network. Lets say about 20 up to 50 devices. Our goal was to support peer-to-peer video streaming over this local network, since the upload capacity of the internet-connection is limited.

 

We have been testing several builds of Linphone for a while now, and we are able to stream through sip.linphone.org testing server. Given the context described above, we have particular interest in the ICE implementation.We have some unresolved issues regarding P2P streaming, we hope somebody could help to clear this up.

 

## Setup

 

Tablet:                                    Samsung Tab Pro (SM-T520)

Android:                                 4.4.2

Linphone SDK:                        https://www.linphone.org/snapshots/android/ last version downloaded on 2 june 2014

Linphone client:                      3.7.0

SIP server:                              sip.linphone.org

STUN server:                          stun.ekiga.net / stun.l.google.com:19302

Router:                                   TP-Link TL-WDR4300

Switch:                                    TP-Link Unmanaged

 

## Test results

 

Using Wireshark for network diagnostics we found some details.

- Either STUN server appears to be working as the clients receive mapped address binding responses.

- Confirm to be able to initiate session and stream with Stun FirewallPolicy for streaming through media relay server over RTP.

- While we are able to initiate a session and stream with the desktop client using ICE FirewallPolicy, we are unable to do so using the Android SDK build.

- Using the desktop client we can see address mapping created for our public ip and xor address mapping for media relay server and other clients and bindings being made between clients. In Android SDK a address mapping is created for our public IP, but we dont see address mapping and binding request being made to the other client address. 

 

## Questions

 

- Is the desktop "default identity", with resolved local address, involved in this process? Then should te behaviour be the same for the Android SDK (also create an default identity)?

- Is the ICE support code the same in both desktop client and Android SDK build?

- Any pointers or common pitfalls, to look for involving ICE issues?

 

- To rule out other factors we are testing against Linphone test server. We have created a sip proxy using Kamalio in previous tests. We were unable to stream at that time, this is because it requires an additional media relay server like Asterisk? We are interested in the Linphone server configuration to be able to host our own.

 

Of course we are happy so supply any diagnostic results if needed.

 

With best regards,

 

Robbert Bakker