\begin{tabular}{|l|l|c|} \hline Q26 & Give two examples of user agents in SIP. & (2 marks) \\ \hline A26 & Student answer & \\ \hline F26 & Assessor feedback: & (marksawarded) \\ \hline \end{tabular} \begin{tabular}{|l|l|c|} \hline Q27 & Explain the three services involved in QoS. & (5 marks) \\ \hline A27 & Student answer & \\ \hline F27 & Assessor feedback: & (marksawarded) \\ \hline \end{tabular} \begin{tabular}{|l|l|c|} \hline Q28 & Discuss (not list) any two VoIP applications in mining. & (4 marks) \\ \hline A28 & Student answer & \\ \hline F28 & Assessor feedback: & (marksawarded) \\ \hline \end{tabular} \begin{tabular}{|l|l|c|} \hline Q29 & What is the role of a proxy server? & (2 marks) \\ \hline A29 & Student answer & \\ \hline \end{tabular}