User Equipment (UE)-to-Network Relay functionality was introduced in Release 13 of the Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) to extend and improve user connectivity. A UE connected to the network (relay UE) provides network access to another UE (remote UE) by establishing a direct one-to-one connection with it using the sidelink (SL) channels over the PC5 interface. The PC5 signaling is used for the establishment and maintenance of this direct connection, and different procedures and timers are linked to these processes. We focus on evaluating the PC5 signaling protocol performance through system-level simulations to provide some insights on minimum timer values that may increase the probability of successfully establishing and maintaining the connection between a remote UE and a relay UE. This data is in multiple forms: - source .txt files that contains data based on network simulations in ns-3. - scripts .gnu files for processing the data and generating plots as shown in NIST Technical Note 2144. - readme file explaining the data and associated scripts. Each .txt file (starting with "DirectSecurityTrace") represents the cumulative distribution function (CDF) of the roundtrip time (RTT) for the security procedure (one set of message exchange: request/response) over ProSe for a specific sidelink period value (e.g. 40, 60, 80, ..., 320 ms). Each .txt file (starting with "DirectCommunicationTrace") represents the cumulative distribution function (CDF) of the roundtrip time (RTT) for direct link setup procedure (one request/response encapsulating another request/response) over ProSe for a specific sidelink period value (e.g. 40, 60, 80, ..., 320 ms). Each .txt file (starting with "DirectCommunicationTrace") represents the success probability of establishing a remote/relay connection for a specific sidelink period value (e.g. 40, 60, 80, ..., 320 ms). The rest of the .txt files (minvaluesfile.txt, avgvaluesfile.txt, maxvaluesfile.txt) includes results from the theoretical model in "Access Time Analysis of MCPTT Off-Network Mode over LTE" by Yishen Sunby Yishen Sun et al (https://doi.org/10.1155/2019/2729370): providing the minimum, maximum, and average values of the RTT over ProSe direct communication. Running the .gnu scripts generates the .eps figures (Fig. 3/4/5) included in NIST Technical Note 2144: They plot the corresponding RTT in function of time (ms) and sidelink period, and the corresponding success probability in function of the sidelink period.