 required to pro- cess PTP, SO the network is implemented as a "hop-by-hop" topology. In this case, PTP is carried by layer 2 (Ethernet) multicast and is implemented according to the G.8275.1 telecom profile. This recommendation specifies those limits that apply to the network model for packet-based distri- bution outlined in G.8271. The limits covered here are the maximum time and phase error generated in the network as well as the minimum phase and time error that the equipment needs to tolerate. From the scope of the recommendation: This Recommendation specifies the maximum network limits of phase and time error that shall not be exceeded. It specifies the minimum equipment tolerance to phase and time error that shall be provided at the boundary of packet networks at phase and time synchronization interfaces. It also outlines the minimum requirements for the synchronization function of network elements. This Recommendation addresses the case of time and phase distribution across a network with packet-based method with full timing support (FTS) to the protocol level from the network. G.8271.1 treats two deployment cases, one where the slave clock is embedded in the end applica- tion (which for mobile means that the radio has a PTP slave clock), and one where the slave clock external to the end application. In this second case, the time signal is passed to the final application via some other method (an example would be a timing signal, such as 1PPS, carrying phase). For each of these two deployment cases, the standard defines limits at various points, A, B, C, D, and E. Point D is hidden in deployment case 1, as it is embedded in the end application. Figure 8-3 shows the deployment case 2 with the non-embedded clock. Deployment case 2 Intra-site time sync interface Network time reference (such as GNSS receiver) Packet network T-TSC End application time clock Figure 8-3 Deployment Case 2 from G.8271.1 with Non-embedded Slave Clock (Based on Fig- ure 7-1 of ITU-T Recommendation G.8271.1) This recommendation inclu