## 6 Evaluation  
We analyze the performance of the proposed algorithms in this section by examining different parameters that is, number of different layers accepted/rejected, bandwidth utilization, and so forth. \begin{table}
\begin{tabular}{l l} \hline \hline
**Notation** & **Description** \\ \hline \(V\) & The set of OF switches, DASH clients, and HTTP-media servers \\ \(D\) & The set of DASH clients \\ \(S\) & The set of HTTP-media servers \\ \(m_{c}\) & The desirable maximum video quality determined by client \(c\in D\) \\ \(B\), \(b_{ij}\) & \(B\) is a two-dimensional array where \(b_{ij}\) shows the available bandwidth between \(i\) and \(j\in V\) \\ \(N\) & Total number of nodes in a topology \\ \(src\) & A dash client \(D\) node in Graph \(G\) \\ \(dest\) & A server node \(S\) in Graph \(G\) \\ \(P_{src\to dest}\) & Path from \(src\) to \(dest\) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Notations. We create a network model of client and servers for evaluation. The model includes a topology of a hundred (100) nodes with two hundred (200) edges. The average topology degree is four (4). The topology is generated using BRITE topology generator [31]. In the evaluation model, ten (10) nodes act as a server, and remaining nodes act as a client. The bandwidth for the client is ten megabits per second (Mbps) and for the servers, its hundred Mbps. All client media requests are randomly generated which includes the selection of video resolution and its layers. We use four SVC layers with different resolutions in SVC-DASH based streaming. The SVC layers include one base layer (BL\({}_{0}\)) and three enhancement layers (EL\({}_{1}\), EL\({}_{2}\), EL\({}_{3}\)). The bit-rate recommendations for SVC layers with different resolutions from 1920 \(\times\) 1080 to 640 \(\times\) 360, are shown in Table 2, which are based on Reference [17]. For extensive analysis, five typologies are generated for the simulations. We evaluate our algorithms with the combination of DS modes that is, processing and forwarding. The two DS modes outcome can be analyzed under four categories as follows:  
* allLayers-multiPath: Send all the client requested SVC layers on different paths. * allLayers-singlePath: Send all the client requested SVC layers on a single path. * layerWise-multiPath: Send each client requested SVC layers on a different path. * layerWise-singlePath: Send each client requested SVC layers on a single path. Now we compare the number of layers accepted by DS with the combination of processing and forwarding modes. It is evident from Figure 7, that scheduler in _allLayer_ processing mode accommodates maximum number of layers as compared to scheduler in _layerWise_ processing mode. Moreover, it also reveals that the number of requests accommodated in _singlePath_ forwarding mode is higher as compared to _multiPath_ forwarding mode. We further analyze our DS by looking into the total number of layers rejected in Figure 8. It can be clearly seen that the scheduler in _singlePath_ forwarding mode rejects less number of layers as compared to the scheduler in _multiPath_ forwarding mode. However, Figures 7 and 8 do not provide the complete \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multicolumn{5}{c}{**SVC Layers Bitrate [kbps]**} \\ \hline
**Resolution** & **Base Layer** & **EL\({}_{1}\)** & **EL\({}_{2}\)** & **EL\({}_{3}\)** \\ \hline
1920 \(\times\) 1080 & 4000 & 1500 & 1700 & 3200 \\ \hline
1280 \(\times\) 720 & 1500 & 1250 & 2050 & 3000 \\ \hline
960 \(\times\) 540 & 1200 & 775 & 725 & 800 \\ \hline
640 \(\times\) 360 & 600 & 390 & 510 & 575 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Scalable Video Coding (SVC) layers bit-rate recommendations derived from industry solutions. Figure 7: SVC Layers accepted. picture of individual layer types rejected, therefore we look briefly at Figures 9 and 10, that provide statistics on types of layers rejected. Figure 9 shows the scheduler in _allLayer_ processing mode rejects base layers.