# Enhancing Real-Time Video Streaming Quality via MPT-GRE Multipath Network
## 7 Experimental Test Environment
### MPT Software Configuration  
The MPT software's configuration is crucial for the experimental setup, especially for enabling the MPT-GRE tunnel functionality. The version used in this experiment is mpt-gre-lib64-2019.tar.gz, a 64-bit version specifically designed for multipath GRE over UDP transport, available from a repository [26]. The MPT installation directory contains  
Figure 4: MPT-GRE multipath network topology of real-time 4K video streaming. two main configuration files that need modification to ensure the proper operation of the MPT-GRE multipath system across the network infrastructure. 1. Interface Configuration: The first configuration file, conf/interface.conf, contains critical parameters related to the network interfaces and tunnels. The following adjustments have been made: 1. _Local Command UDP Port Number_: Defines the port for managing communication between the MPT software and the network interfaces. 2. _Interface Number and Tunnel Information_: Specifies the interface number, maximum transfer unit, and acceptance of remote requests. It also defines the tunnel interface's name and assigns an IPv4 address and a prefix length to indicate the subnet. 3. _Tunnel Management_: Details the management of the tunnel interface, ensuring that the software can handle traffic routes through the MPT-GRE tunnel effectively. A similar configuration was applied to the second server's interface to maintain consistency in the setup, enabling a fully functional multipath environment. 2. Tunnel and Connection Configuration: The second configuration file, conf/connections/IPv4.conf, organizes the logical connections and defines the paths for data transmission. Each MPT-GRE tunnel is organized into separate connection files, specifying the relevant IP addresses for both tunnel endpoints. The configuration utilizes IPv4 encapsulation within an IPv4 GRE tunnel, enabling the multipath routing of video packets between the two servers across multiple physical network paths. Constant-length data fields ensure consistent packet formatting for GRE encapsulation. Previous work has provided detailed documentation of these configuration settings on GitHub [27]. These configurations form the backbone of the MPT software's ability to aggregate and manage multiple network paths, enabling more reliable and efficient video transmission across the MPT-GRE tunnel. By setting up and adjusting the MPT software with these parameters, the experiment can evaluate the effects of MPT-GRE on video streaming performance in real time. This configuration ensures that video data are split and transmitted over multiple paths, offering improved resilience against network failures and potentially enhancing the overall quality of the end-user experience. To conduct the experiment and ensure controlled network conditions, the transmission speed of both network paths was set to \(x\) Mbps using the Traffic Control (tc) command, where x represents the transmission speeds as follows: _tc qdisc add dev eth1 root tbf rate xmbit burst 32 kbit latency 100 ms_  
This setup enforces a consistent bandwidth limit on each path, allowing for a more accurate analysis of the MPT-GRE tunnel's performance in a controlled network environment. The video streaming process was initiated from the first Dell PowerEdge R620 server, which acted as the sender, with the VLC media player handling video playback and streaming. The H.264 codec was chosen for its efficiency in video compression and widespread use in streaming applications. The HTTP protocol was used to stream the video over both the single path and the MPT-GRE tunnel. HTTP is commonly chosen for video streaming due to its compatibility and ease of use in networked environments. On the receiver side, the video stream was collected via two methods. First, the video was received at the tunnel's destination IP address (10.0.0.2) through the MPT-GRE tunnel (tun0), achieving a throughput approximately equal to the sum of the two physical paths.