# A Versatile Resilience Packet Ring Protocol Model for Homogeneous Networks
###### Abstract
When a packet reaches the foreign agent, it removes the IP header and encapsulates the original IP datagram in a network-level Protocol Data Unit (PDU). After encapsulation, it sends the entire IP datagram to node A. Step 4. When mobile node A wants or needs to send data to server X, it uses its static IP address. Step 5. When mobile node A sends data towards server X, it directly reaches server X using its static IP address. There are three steps to perform a mobile IP operation; it performs three tasks. The first task is discovering, which means the mobile node finds home agents and foreign agents. Mobile nodes use the registration process to inform their home agent about the CoA. Finally, the purpose of tunneling is to forward the IP datagram from the home address to the CoA [4; 5]. The concept of the Virtual IP address (VIP) layer was introduced by the Victor Company of Japan (JVC) in 2003. According to the company, seamless communication between optical and Radio-Frequency (RF) wireless Local Area Networks (LAN) is possible if we create one intermediate virtual layer called the VIP layer between two network interface cards (NIC). To prove their concept, they perform one experiment. The client machine creates an Internet Protocol (IP) tunnel between the devices with the relay server's destination address. There will be two tunnels between the client and the relay server. The relay server is further connected to the main server. The routing table of the router controls the whole complete situation and determines who can switch between two tunnel devices. With this simple method, seamless communication between two different NICs is assured [6]. More information material about the VIP layer and its benefits is available in [6]. As mentioned above, two different NICs use two different IP addresses. The problem in the Windows Operating System (OS), during the shifting of the connection between two IP sessions, is that the connection will be dropped [7; 8; 9]. Network nodes with a wireless interface and wired interface must have two different IP addresses if both are working simultaneously; otherwise, there will be a conflict of IP addresses. During handover or shifting the user from a wired link to a wireless link or wireless to a wired link, the current IP address will be changed. When the IP changes, its session and address are changed and lost. It will connect to the DHCP to obtain a new IP and start a new session. The whole process will take at least 30 s even using the Windows Bridge function. A delay of 30 s means a break in communication. To overcome this problem, the new concept of a virtual miniport or virtual port is introduced. In this method, when a user of one domain has a wired connection, removes its wired connection, and enters the second domain, its communication will not break. Figure 2 illustrates an example of this technique. In this example, a mobile node moves from one domain to a second domain and uses 802.11b and 802.3 access technology. It creates one virtual miniport or driver that communicates with the wireless and wired NIC simultaneously. To provide the handover procedure, we used the Windows OS Network Driver Interface Specification (NDIS), as shown in Figure 3. Two models are presented; the first model communicates with the network card and keeps a record of ongoing and incoming traffic. The interface manager lies between the legacy protocol driver and the lower network card driver. The purpose is to use an intermediate protocol driver to support the virtual network port and multiplexing of 802.11b and 802.3. When a virtual miniport is created, a single IP address will be assigned to that port. In the case of network failure, the IP address will be the same, and there will be no connection loss. According to [10], during the handover process, the session will be lost. Therefore, to overcome this problem, almost the same concept is used with the MIH function. In this method, an intermediate driver is present between the protocol driver and the actual miniport driver.