# A Versatile Resilience Packet Ring Protocol Model for Homogeneous Networks
## 2 Related Work
### VRPR Packet Flow When a Packet Enters a GW Router  
When a packet is received, a router has to check whether it is an acknowledgment or a new packet. If it is a new packet, then it is sent to the high-priority link. If this is an acknowledgment, then it is sent to the same link from whence it came [18]. When going towards the internal server, a packet reaches the WLAN Access Point (AP), and if the AP finds that the link from the AP to the server is down, it will route traffic towards the AP to the LAN switch. The LAN switch will send the traffic towards the server. We designed the logical diagram VRPR (shown in Figure 6), which is a new concept proposed and tested for the LAN only. In the future, we can propose the same a network model for the MAN and WAN. We have tested VRPR in the prior monitoring of the link model. This means that, when a packet enters a switch, the switch checks the status of the outgoing link. If the link is available, it sends a packet on the main link; otherwise, it sends the packet on an alternative link. If the switch is sending a packet on the main link and the transmission of the packet link is broken, there will be a packet loss. This is an infrequent possibility; however, we plan to develop a solution for this limitation in the future. We have used Layer 3 switches. This is a wired switch having optical ports and copper ports. The access switch sends a 'Hello' packet to its connecting devices and checks the link status when the packet reaches the switch. It is the responsibility of the access switch to check the status of the link. If the link is down, then the switch will send this packet towards the secondary link (in our case, the switch to the access point link is the secondary or alternative link). The function of the access points is the same as that of the access switch. This access point should support 802.11g for high-speed data transfer. An access point has wired ports. This access point is a wired and wireless switch. The role of the gateway router is significant in our proposed network model. We have suggested adding some more intelligence to a gateway router. When the packet reaches the switch from the wired link, it will first send it to the gateway router, which keeps traces of its path. Our proposed VRPR-based network model is a complete suite. It is implemented in a server, switch, access point, and gateway router. The internal network consists of two rings. The first ring consists of a server, access point, and switch. The second ring consists of an access point, switch, and router. We have selected only one server to understand the working of our model better. The server is connected to one Layer 3 (L3) access switch via a fiber cable. The server is also connected to an access point via a wireless link of 802.11g. The access switch and access point are connected to a fiber cable and these two devices are connected to the gateway router. The gateway router is connected to the Internet Service Provider (ISP) cloud. We also include one external server to complete the network. The scope of VRPR is only within one data center. We propose some advanced features in the server, access switch, access point, and gateway router. Servers can either be blade servers or regular servers, but in our proposed network model, the primary purpose is to generate a packet and to generate a duplicate of each packet. After duplicating a packet, the server sends one copy to the wireless network card and sends another copy to the wired network card. In addition, we propose optical ports in servers. When a wireless packet reaches the GW router, the GW router will compare it with the traces of the path of the wired packet. If the same packet is received, then the router will discard the wireless packet. If the router received only packets from a wireless link, it would assume that the wired link is down and it sends out the wireless packets.