WO2014112863A1

WO2014112863A1 - A wireless access device, system and method for routing multicast traffic

Info

Publication number: WO2014112863A1
Application number: PCT/MY2014/000006
Authority: WO
Inventors: Sridhar Sivanand; Mohammad Zarin ABDUL AZIZ; Chrishanton VETHANAYAGAM; Jugnu JETHI; Shariq Haseeb
Original assignee: Mimos Berhad
Priority date: 2013-01-18
Filing date: 2014-01-13
Publication date: 2014-07-24
Also published as: MY170191A

Abstract

A wireless access device (100), system (200) and method for routing multicast traffic for nodes between a first network and a second network has been disclosed. The wireless access device (100) comprises a backhaul module (10) for receiving packets from the first network and a multicast module (40) for checking the multicast translation table (90) and converting the multicast packets to a Multimedia Access Control (MAC) layer unicast packets. The multicast module (40) is further adapted for forwarding the MAC layer unicast packets to the access module (70) through the second bridge module (60). The access module (70) is adapted for forwarding the MAC layer unicast packets to subscribed nodes on the second network.

Description

A WIRELESS ACCESS DEVICE, SYSTEM AND METHOD FOR ROUTING MULTICAST

TRAFFIC

FIELD OF THE INVENTION

The present invention relates to a wireless access device, system and method for routing multicast traffic on a Wireless Access Point (WAP).

BACKGROUND ART

There are many conventional delivery formats available to send data or information in packets across a network in the Internet architecture to one or more recipients. One of them is IP multicast. What that actually sets the IP multicast apart from other delivery formats such as IP broadcast, unicast, and anycast is that when it comes to the delivery of IP datagrams such as streaming media and Internet TV, IP multicast is often used. Thus, this is the reason why those datagrams such the streaming media are referred to as multicast traffic. Also, IP multicast is in fact a form of delivering IP messages or information, particularly afore-said IP datagrams to a group of recipients in a single transmission. In other words, such an IP multicast can be considered as a one-to-many data transmission or communication across a network within the IP infrastructure. Apart from this, many-to- many IP communication can also take place in the IP multicast.

Even though it is commonly called the IP multicast, in actual fact, multicasting is only involved at the routing levels. Routers are tasked to generate as many as it can distribution paths for the IP datagrams to transmit through the IP network to the multicast destination addresses respectively.

Due to its nature of one-to-many or many-to-many IP communication, the IP multicast does not or seldom replicate the packets it sends to the multicast recipients. Unless replicating the packets is necessary in the network, the packets are replicated but usually at those network nodes such as the routers. In spite of the above, what IP multicast more than makes up for its ability in one-to-many or many-to-many IP communication, it lacks in its ability to transmit in different environment. Such an instance is real when the multicast traffic is required to transmit over wireless networks.

One of the identified problems stem from the fact that there is no multicast support being available or that the multicast support is not sufficient on wireless links. This is further true as the multicast routing only occurs at those routers as mentioned above. It has been often the case that the multicast traffic is treated as broadcast traffic in wireless networks. As such, the data of the multicast traffic are often throttled at a basic data rate instead of being distributed at their own optimal rate.

Such a problem is even more aggravated when the source of the multicast traffic in a network is connected to the Wide Area Network (WAN) port of a Wireless Access Point (WAP). It should be noted that typically, the WAP does not have a means to route the multicast traffic from one network to another, particularly or as an example, from a WAN port to a Wireless Local Area Network (WLAN) port on the WAP or vice versa. Such a situation is also extended to the handling of the routing of the multicast subscriptions.

In light of the above, there is felt a need for a wireless access device, system and a method which is not only able to overcome the above shortcomings but also route multicast traffic and subscriptions from one network to a different type of network in a wireless environment and vice versa. There is also felt a need for a wireless access device and a method which can route multicast traffic to and fro between a WAN port and a WLAN port.

SUMMARY OF THE INVENTION

For the purpose of this specification, the term 'traffic' relates to both multicast packets as well as multicast subscription messages which are transmitted between one or more networks.

Further, the term 'node' in this specification relates to an electronic device including a computer, a laptop, a wireless mobile device and the like computing device that is attached to a network and is capable of sending, receiving, or forwarding information over a communication channel.

In accordance with a first aspect of the present invention there is provided a wireless access device for routing multicast traffic for nodes between a first network and a second network, the wireless access device comprising a multicast subscription module (120) for maintaining multicast subscription of nodes hosted on a second network; a backhaul module for receiving traffic from the first network; a multicast packet identifier module cooperating with the backhaul module for receiving the traffic, the multicast packet identifier module adapted to check and differentiate the traffic between non-multicast packets and multicast packets; a multicast module having a multicast translation table, the multicast module adapted to receive and convert the multicast packets to at least one Multimedia Access Control (MAC) layer unicast packets using the multicast translation table; and an access module adapted to receive the MAC layer unicast packets from the multicast module and route the MAC layer unicast packets to subscribed nodes.

Typically, the first network and the second network are selected from the group of networks consisting of a Wide Area Network (WAN), a Local Area Network (LAN) and a Wireless Local Area Network (WLAN). Preferably, the multicast translation table is adapted to store at least one address selected from the group of addresses consisting of MAC address of a node, a destination hardware address and a destination IP address; and the multicast module is adapted to convert the multicast packets to the Multimedia Access Control (MAC) unicast packets based on the addresses stored in the multicast translation table.

Further, the multicast module converts the multicast packets to the MAC layer unicast packets based on number of nodes associated with the multicast packet.

Still further, the wireless access device comprises a multicast virtual interface adapted to receive the multicast packets from the multicast packet identifier module and forward the multicast packets to the multicast module; and a first bridge to facilitate forwarding of the multicast packets from the multicast virtual interface to the multicast module.

In addition, the wireless access device comprises a second bridge to facilitate forwarding of the MAC unicast packets from the multicast module to the access module. Furthermore, the multicast subscription module processes a multicast subscription message based traffic received from the backhaul module and sends the multicast subscription message to the first network, wherein the multicast module is adapted for receiving and checking a multicast subscription message and based on the type of subscription message further adapted to update the multicast translation table.

In accordance with a second aspect of this invention, there is provided a system for routing multicast traffic for nodes between a first network and a second network on a wireless access point, the system comprising a backhaul module for receiving traffic from the first network; a multicast packet identifier module co-operating with the backhaul module for receiving the traffic, the multicast packet identifier module (20) adapted to check and differentiate the traffic between non-multicast packets and multicast packets; a multicast module having a multicast translation table for storing at least one address associated with the nodes subscribed to multicast, the multicast module adapted to receive and convert the multicast packets to at least one Multimedia Access Control (MAC) layer unicast packets using the multicast translation table; and an access module adapted to receive the MAC layer unicast packets from the multicast module and route the MAC layer unicast packets to the subscribed nodes. Typically, the first network and the second network is selected from the group of networks consisting of a Wide Area Network (WAN), a Local Area Network (LAN) and a Wireless Local Area Network (WLAN).

Preferably, the multicast translation table is adapted to store at least one address of the subscribed nodes selected from the group of addresses consisting of a MAC address of a node, a destination hardware address and a destination IP address, and the multicast module is adapted to convert the multicast packets to the Multimedia Access Control (MAC) unicast packets based on the addresses stored in the multicast translation table. Further, the multicast module converts the multicast packets to the MAC layer unicast packets based on number of nodes subscribed to the multicast packet.

Still further, the system further comprises a multicast virtual interface adapted to receive the multicast packets from the multicast packet identifier module and forward the multicast packets to the multicast module; and a first bridge to facilitate forwarding of the multicast packets from the multicast virtual interface to the multicast module.

In addition, the system further comprises a second bridge to facilitate forwarding of the MAC unicast packets from the multicast module to the access module.

Furthermore, the system comprises a multicast subscription module adapted to process a multicast subscription message based traffic received from the backhaul module and send the multicast subscription message to the first network, wherein the multicast module is adapted for receiving and checking a multicast subscription message and based on the type of subscription message is further adapted to update the multicast translation table.

In accordance with a third aspect of the present invention, there is provided a method for routing multicast traffic for nodes between a first network and a second network using the wireless access device, the method comprising the steps of receiving and forwarding traffic from a first network to a multicast packet identifier module by using a backhaul module; checking and differentiating the traffic between non-multicast packets and multicast packets by using the multicast packet identifier module; forwarding the multicast packets to a multicast virtual interface by using the multicast packet identifier module; forwarding the multicast packets to a multicast module through a first bridge module by using the multicast virtual interface; checking the multicast translation table and converting the multicast packets to at least one Multimedia Access Control (MAC) layer unicast packets by using the multicast module; forwarding the MAC layer unicast packets to an access module through a second bridge module by using the multicast module; and forwarding the MAC layer unicast packets to nodes on a second network by using the access module.

Typically, the step of checking and differentiating the traffic between non-multicast packets and multicast packets includes forwarding non-multicast packets to a relatively higher layer on a protocol stack by using the multicast packet identifier module.

Preferably, the step of converting the multicast packets to Multimedia Access Control (MAC) layer unicast packets includes the step of converting the multicast packets to the MAC layer unicast packets based number of nodes associated with the multicast packets and using addresses including an MAC address of each of the nodes associated with the multicast packets, a destination hardware address and a destination Internet Protocol (IP) address. Furthermore, the step of receiving and forwarding traffic from a first network includes the steps of following receiving and checking a multicast subscription message based traffic by the backhaul module; adding an entry for a new multicast address into the multicast translation table, and sending an adding notification for the new multicast address to a multicast subscription module by using the multicast module, if the multicast subscription message is a request for a new multicast address that does not consist of a node; sending a join multicast subscription message for the new multicast address to the first network through the backhaul module by using the multicast subscription module; and removing the entry of the multicast address from the multicast translation table, and sending a deleting notification for the multicast address to the multicast subscription module by using the multicast module, if the multicast subscription message is a request to leave the multicast address; and sending a leave multicast subscription message to the first network through the backhaul module by using the multicast subscription module. The present invention consists of certain novel features and a combination of parts hereinafter fully described and illustrated in the accompanying drawings and particularly pointed out in the appended claims; it being understood that various changes in the details may be without departing from the scope of the invention or sacrificing any of the advantages of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of facilitating an understanding of the invention, there is illustrated in the accompanying drawings the preferred embodiments from an inspection of which when considered in connection with the following description, the invention, its construction and operation and many of its advantages would be readily understood and appreciated.

FIG. 1 shows the routing of the multicast traffic from a Wide Area Network (WAN) port to a Local Area Network (LAN)/Wireless Local Area Network (WLAN) ports using the wireless access device envisaged by the present invention;

FIG. 2 shows a block diagram of the wireless access device for routing multicast traffic in accordance with this invention; FIG. 3 shows a schematic of the system for routing multicast traffic in accordance with this invention;

FIG. 4 shows a flowchart in relation to the multicast subscription through a first network in accordance with this invention; and

FIG. 5 shows a flowchart in relation to the routing of the multicast traffic from the first network in accordance with this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A detailed description of the preferred embodiments of the invention is disclosed herein. It should be understood, however that the preferred embodiments are merely exemplary of the invention, which may be embodied in various forms or configurations. Therefore, the details disclosed herein are not to be interpreted as limiting but merely as the basis for the claims and for teaching one skilled in the art of the invention. It is envisioned that those skilled in the art may devise various modifications without departing from the scope of the appended claim.

Wireless access points are conventionally hardware devices which enable wireless nodes / node devices to receive and transmit information on a wired network using standards including Wi-Fi. Thus, wireless access points enable routing of traffic on a particular network to which they are connected. However, these devices do not perform the task of routing multicast traffic to and fro between one network to a different type of network in a wireless environment. Particularly, across subnets for example, between a WAN port and a WLAN port. Thus, to overcome this shortcoming of the conventional wireless access point devices, the present invention envisages a wireless access device and a method for routing multicast traffic across subnets. The term subnet relates to two or more discrete networks which form a part of an IP network.

Referring to the accompanying drawings, FIG. 1 illustrates an exemplary diagram showing routing of the multicast traffic from a first network to a second network using the wireless access device (100) envisaged by the present invention.

As represented in the drawings, according to one aspect of the present invention, particularly to FIG. 2, which shows a block diagram for the wireless access device (100) for routing multicast traffic for nodes between a first network and a second network or between subnets.

The wireless access device (100) envisaged by the present invention does not require any changes (hardware or software) to be performed to the nodes or node devices for routing multicast traffic across subnets. Furthermore, the wireless access device (100) eliminates the overheads of encapsulating multicast traffic within unicast headers and using unicast routing protocols for performing the routing. The aforementioned overheads are eliminated as in accordance with the present invention the multicast packet routing is handled within the envisaged wireless access device (100) itself. Referring to FIG. 2, the wireless access device (100) for routing multicast traffic across subnets comprises a backhaul module (10) for receiving packets from a first network for example a WAN port, a multicast packet identifier module (20), a first and a second bridge modules (50, 60), a multicast virtual interface (30), a multicast module (40) having a multicast translation table (90), and an access module (70) to route packets to nodes hosted on a second network for example a LAN / WLAN port.

Referring to FIG. 2 & 5, the backhaul module (10) is adapted to forward the received packets to the multicast packet identifier module (20). The multicast packet identifier module (20) checks and differentiates the packets between non-multicast packets and multicast packets. In accordance with this invention the multicast packet identifier module (20) uses the destination MAC address and/or the destination IP address in the packet to determine if the packet is a multicast packet.

If the packets are identified as the non-multicast packets, the multicast packet identifier module (20) forwards the non-multicast packets to a relatively higher layer on a protocol stack (80).

Referring again to FIG. 2 & 5, the multicast packet identifier module (20) forwards the identified multicast packets to the multicast virtual interface (30). The multicast virtual interface (30) forwards the multicast packets to the multicast module (40) through the first bridge module (50).

In accordance with the first aspect of this invention, the multicast packet identifier module (20) facilitates the present invention to transfer traffic within the wireless access device (100) for transmission unlike prior art wherein unicast routing protocols are used to route traffic. The prior art relies on either its (i) network stack forwarding architecture to forward multicast packets, or (ii) creation of unicast tunnels for transferring multicast traffic to other network devices. Thus, prior art uses either layer 3 capable or router purposed design capable devices for advanced routing ability. The wireless access device (100) of the present invention however circumvents usage of any network stack forwarding architecture; instead it uses the multicast packet identifier module (20) which inspects every packet which arrives at the backhaul module (10) before traversing the packet up to the protocol stack. If a multicast packet is successfully inspected, the packet is accordingly segregated and injected directly into the multicast virtual interface (30) for modification of its source device originator to the multicast virtual interface (30), for successful transfer of the multicast packet across for instance, WAN to WLAN separated subnets within the device ( 00).

Further, the multicast module (40) is adapted to check the multicast translation table (90) and convert the multicast packets into a number of layer 2 Multimedia Access Control (MAC) layer unicast packets.

The multicast module (40) then further forwards the MAC layer unicast packets to the access module (70) through the second bridge module (60). The access module (70) is adapted to forward the MAC layer unicast packets to nodes. In accordance with this invention, the first bridge module (50) and the second bridge module (60) link two or more network interfaces so that their segments become part of the same subnet using bridging.

Still further, the multicast module (40) is the central control mechanism of the wireless access device (100). Along with the operation of translating incoming IP multicast traffic to outgoing MAC layer unicast traffic, the multicast module (40) manages multicast message subscriptions.

Referring to FIG. 2 & 4, the wireless access device (100) is further adapted to process a multicast subscription received through a first network, for example WAN. The wireless access device (100) further comprises a multicast subscription module (120). In order to route multicast subscription requests across different networks through the wireless access device (100) the present invention utilizes the multicast subscription module (120) in conjunction with the multicast module (40). The multicast module (40) facilitates nodes connected to a second network (for example WLAN port) to subscribe to multicast addresses on a first network (for example WAN port).

In accordance with the first aspect of this invention, the wireless access device (100) is triggered by multicast subscriptions. The wireless access device (100) receives the multicast subscriptions from nodes connected to a second network for example WLAN network and only relays the subscription messages through the Multicast Subscription Module (120) to trigger the first network for example, WAN network to subscribe to the respective multicast address. Hence, only multicast traffic that has subscribers on the second network receive packets transferred from the first network (WAN) to the second network (WLAN). All other multicast traffic are not transferred across the first network (WAN) and the second network (WLAN). On the other hand, the prior art does not include any trigger mechanism and therefore forwards all multicast traffic and subscription flows from one network device to another as long as there is a forwarding/routing/tunneled path which exists between those network devices. Furthermore, the multicast module (40) receives and checks a multicast subscription message. If the multicast subscription message is found to be a request for a new multicast address that does not consist of a node, the multicast module (40) adds an entry for the new multicast address into the multicast translation table (90), and sends an adding notification for the new multicast address to the multicast subscription module (120). The multicast subscription module (120) then sends a join multicast subscription message for the new multicast address to the first network (for example WAN) through the backhaul module (10).

If the multicast subscription message is a request to leave the multicast address with no more nodes, the multicast module (40) removes the entry of the multicast address from the multicast translation table (90), and sends a deleting notification for the multicast address to the multicast subscription module (120). The multicast subscription module (120) then sends a leave multicast subscription message for the multicast subscription message for the multicast address to the first network (for example WAN) through the backhaul module (10).

Regarding the multicast module (40), with reference to FIG. 5, the multicast module (40) converts the multicast packets to the MAC layer unicast packets depending on the number of the nodes. The multicast module (40) converts the multicast packets to the MAC layer unicast packets through using a MAC address of a node, or either a destination hardware address or a destination Internet Protocol (IP) address.

Regarding the multicast subscription, upon checking the multicast subscription message, if the multicast subscription message is a request for a multicast address that consists of a node, no entry for the multicast address is added to the multicast translation table (90) and no adding notification for the multicast address is sent to the multicast subscription module (120).

In accordance with a second aspect of this invention, there is provided a system (200) for routing multicast traffic for nodes between a first network and a second network on a wireless access point as seen in FIG. 3.

Referring to FIG. 3, the system (200) comprising a backhaul module (202) for receiving traffic from the first network. The backhaul module (202) forwards the traffic to a multicast packet identifier module (204) which receives the traffic and checks and differentiates it between non-multicast packets and multicast packets. The multicast packets are further forwarded to a multicast module (206) via a multicast virtual interface (212) using a first bridge (214). The first bridge (214) virtually connects the multicast module (206) to the first network.

The multicast module (206) further includes a multicast translation table (208) for storing at least one address associated with the nodes subscribed to multicast. The multicast module (206) performs the operations of receiving and converting the multicast packets to at least one Multimedia Access Control (MAC) layer unicast packets using the multicast translation table (208). Additionally, the multicast module (206) converts the multicast packets to the MAC layer unicast packets based on number of nodes subscribed to the multicast packet.

In accordance with the second aspect of this invention, the multicast translation table (208) is adapted to store at least one address of the subscribed nodes selected from the group of addresses consisting of a MAC address of a node, a destination hardware address and a destination IP address, and the multicast module (206) is adapted to convert the multicast packets to the Multimedia Access Control (MAC) unicast packets based on the addresses stored in the multicast translation table (208). The system (200) also includes an access module (210) which receives the MAC layer unicast packets from the multicast module (206) and routes the MAC layer unicast packets to the subscribed nodes.

The MAC layer unicast packets are forwarded from the multicast module (206) to the access module (210) via a second bridge (216). The second bridge (216) virtually interfaces the multicast module (206) to the second network to facilitate routing of the MAC layer unicast packets to the subscribed nodes of the second network.

Typically, the system (200) is embedded in the wireless access device (100) and facilitates in routing multicast packets across networks, wherein the first network and the second network is selected from the group of networks consisting of a Wide Area Network (WAN), a Local Area Network (LAN) and a Wireless Local Area Network (WLAN).

Furthermore, the system (100) comprises a multicast subscription module (218) which processes multicast subscription message based traffic received from the backhaul module (202) and sends the multicast subscription message to the first network. The multicast subscription module (218) works in conjunction with the multicast module (206), wherein the multicast module (206) receives and checks a multicast subscription message and based on the type of subscription message updates the multicast translation table (208). Referring now to FIG. 2 & 5, according to a third aspect of the present invention, the present invention is related to a method for routing multicast traffic and subscription messages from one network to another for example, from a Wide Area Network (WAN) port to a Wireless Local Area Network (WLAN) port using a wireless access device (100). The method is conducted by using the wireless access device (100).

As a first step, packets from a first network are received and forwarded to a multicast packet identifier module (20) by using a backhaul module (10). Next, the packets are checked and differentiated between non-multicast packets and multicast packets by using the multicast packet identifier module (20).

As a next course of action, the non-multicast packets are forwarded to a relatively higher layer on a protocol stack (80) by using the multicast packet identifier module (20). The multicast packets are forwarded to a multicast virtual interface (30) by using the multicast packet identifier module (20). The multicast packets are forwarded by the multicast virtual interface (30) to a multicast module (40) through a first bridge module (50).

By using the multicast module (40), the multicast translation table (90) is checked, and the multicast packets are converted to a Multimedia Access Control (MAC) layer unicast packets. The MAC layer unicast packets are then sent to an access module (70) through a second bridge module (60) using the multicast module (40). Finally, the access module (70) forwards the MAC layer unicast packets to nodes.

Referring to FIG. 4, the method is further adapted to process a multicast subscription from the second network (for example WLAN port) through the first network (for example WAN port). There are therefore further steps in the present method as will be hereinafter described.

Firstly, a multicast subscription message is received and checked by the backhaul module (10). If the multicast subscription message is a request for a new multicast address that does not consist of a node, an entry for the new multicast address is added into the multicast translation table (90).

An adding notification for the new multicast address is subsequently sent to a multicast subscription module (120) by using the multicast module (40). Next, a join multicast subscription message for the new multicast address is sent to the WAN through the backhaul module (10) by using the multicast subscription module (120). If the multicast subscription message is found to be a request to leave the multicast address without any nodes left for the multicast address after leaving, the entry of the multicast address would be instantly removed from the multicast translation table (90). A deleting notification for the multicast address would be sent to the multicast subscription module (120) by using the multicast module (40). Subsequently, a leave multicast subscription message for the multicast subscription message for the multicast address would be sent by using the multicast subscription module (120) to the WAN through the backhaul module (10). As an example, with reference to FIG. 1 , in order to route multicast traffic across different networks, the networks are connected to the envisaged wireless access device (100), the present invention proposes the use of a multicast packet identifier module (20) that selectively acquires multicast packets from the first network (for example Wireless Access Network (WAN) port interface) and transfers them to a multicast virtual interface (30) that is bridged to the multicast module (40). In order to route multicast subscription requests across different networks through the envisaged wireless access device (100), the present invention proposes the use of a Multicast Subscription Module (120) which, in conjunction with the Multicast Module (40) subscribes the nodes to a multicast addresses on the first network (WAN port) on behalf of the second network (WLAN) based nodes subscribing to multicast.

When the multicast packets are converted to Multimedia Access Control (MAC) layer unicast packets, the multicast packets are converted depending on the number of the nodes that is, the number of nodes that have subscribed to multicast and have been added in the multicast translation table (90).

The multicast packets are further converted to the MAC layer unicast packets taking into account a MAC address of a node and either a destination hardware address or a destination Internet Protocol (IP) address.

During the checking of a multicast subscription message, if the multicast subscription message is a request for a multicast address consisting of a node, no entry for the multicast address will be added to the multicast translation table (90) and hence no adding notification for the multicast address will be sent to the multicast subscription module (120). While in the foregoing specification this invention has been described in relation to certain preferred embodiments thereof and many details have been set forth for purpose of illustration, it will be apparent to those skilled in the art that the invention is susceptible to additional embodiments and that certain of the details described herein can be varied considerably without departing from the basic principles of the invention.

Claims

1. A wireless access device (100) for routing multicast traffic for nodes between a first network and a second network, said wireless access device (100) comprising:

i. a multicast subscription module (120) for maintaining multicast subscription of nodes hosted on a second network;

ii. a backhaul module (10) for receiving traffic from the first network;

iii. a multicast packet identifier module (20) co-operating with said backhaul module (10) for receiving the traffic, said multicast packet identifier module (20) adapted to check and differentiate the traffic between non-multicast packets and multicast packets;

iv. a multicast module (40) having a multicast translation table (90) for storing at least one address associated with the subscribed nodes, said multicast module (40) adapted to receive and convert said multicast packets to at least one Multimedia Access Control (MAC) layer unicast packets using said multicast translation table (90); and

v. an access module (70) adapted to receive said MAC layer unicast packets from said multicast module (40) and route said MAC layer unicast packets to said subscribed nodes, wherein said multicast module (40) is further adapted for checking a multicast subscription received from said multicast subscription module (120) and correspondingly update said multicast translation table (90).

2. The wireless access device (100) as claimed in claim 1 , wherein said first network and said second network is selected from the group of networks consisting of a Wide Area Network (WAN), a Local Area Network (LAN) and a Wireless Local Area Network (WLAN).

3. The wireless access device (100) as claimed in claim 1 , wherein said multicast translation table (90) is adapted to store at least one address of said subscribed nodes selected from the group of addresses consisting of a MAC address of a node, a destination hardware address and a destination IP address, and said multicast module (40) is adapted to convert said multicast packets to said Multimedia Access Control (MAC) unicast packets based on said addresses stored in said multicast translation table (90).

The wireless access device (100) as claimed in Claim 1 , wherein said multicast module (40) converts said multicast packets to said MAC layer unicast packets based on number of nodes subscribed to said multicast packet.

The wireless access device (100) as claimed in claim 1 , wherein said wireless access device (100) further comprises:

i. a multicast virtual interface (30) adapted to receive said multicast packets from said multicast packet identifier module (20) and forward said multicast packets to said multicast module (40); and

ii. a first bridge (50) to facilitate forwarding of said multicast packets from said multicast virtual interface (30) to said multicast module (40).

iii. a second bridge (60) to facilitate forwarding of said MAC unicast packets from said multicast module (40) to said access module (70).

The wireless access device (100) as claimed in claim 1 , wherein said multicast subscription module (120) is adapted to process a multicast subscription message based traffic received from said backhaul module (10) and send said multicast subscription message to the first network.

A system (200) for routing multicast traffic for nodes between a first network and a second network on a wireless access point, said system (100) comprising:

i. a backhaul module (202) for receiving traffic from the first network;

ii. a multicast packet identifier module (204) co-operating with said backhaul module (202) for receiving the traffic, said multicast packet identifier module (20) adapted to check and differentiate the traffic between non-multicast packets and multicast packets;

iii. a multicast module (206) having a multicast translation table (208) for storing at least one address associated with the nodes subscribed to multicast, said multicast module (206) adapted to receive and convert said multicast packets to at least one Multimedia Access Control (MAC) layer unicast packets using said multicast translation table (208); and

iv. an access module (210) adapted to receive said MAC layer unicast packets from said multicast module (206) and route said MAC layer unicast packets to the subscribed nodes.

8. The system (200) as claimed in claim 8, wherein said first network and said second network is selected from the group of networks consisting of a Wide Area Network (WAN), a Local Area Network (LAN) and a Wireless Local Area Network (WLAN).

9. The system (200) as claimed in claim 8, wherein said multicast translation table (208) is adapted to store at least one address of said subscribed nodes selected from the group of addresses consisting of a MAC address of a node, a destination hardware address and a destination IP address, and said multicast module (206) is adapted to convert said multicast packets to said Multimedia Access Control (MAC) unicast packets based on said addresses stored in said multicast translation table (208).

10. The system (200) as claimed in claim 8, wherein said multicast module (206) converts said multicast packets to said MAC layer unicast packets based on number of nodes subscribed to said multicast packet.

1 1. The system (200) as claimed in claim 8, wherein said system (200) further comprises: i. a multicast virtual interface (212) adapted to receive said multicast packets from said multicast packet identifier module (204) and forward said multicast packets to said multicast module (206); and

ii. a first bridge (214) to facilitate forwarding of said multicast packets from said multicast virtual interface (212) to said multicast module (206).

iii. a second bridge (216) to facilitate forwarding of said MAC unicast packets from said multicast module (206) to said access module (210).

12. The system (200) as claimed in claim 8, wherein said system comprises a multicast subscription module (218) adapted to process a multicast subscription message based traffic received from said backhaul module (202) and send said multicast subscription message to the first network, wherein said multicast module (206) is adapted for receiving and checking a multicast subscription message and based on said type of subscription message is further adapted to update said multicast translation table

13. A method for routing multicast traffic for nodes between a first network and a second network on a wireless access point, said method comprising the following steps:

i. receiving and forwarding traffic from a first network to a multicast packet identifier module (20) by using a backhaul module (10);

ii. checking and differentiating the traffic between non-multicast packets and multicast packets by using the multicast packet identifier module (20); iii. forwarding the multicast packets to a multicast virtual interface (30) by using the multicast packet identifier module (20);

iv. forwarding the multicast packets to a multicast module (40) through a first bridge module (50) by using the multicast virtual interface (30);

v. checking the multicast translation table (90) and converting the multicast packets to at least one Multimedia Access Control (MAC) layer unicast packets by using the multicast module (40);

vi. forwarding the MAC layer unicast packets to an access module (70) through a second bridge module (60) by using the multicast module (40); and vii. forwarding the MAC layer unicast packets to subscribed nodes on a second network by using the access module (70).

14. The method as claimed in claim 16, wherein the step of checking and differentiating the traffic between non-multicast packets and multicast packets includes forwarding non-multicast packets to a relatively higher layer on a protocol stack (80) by using the multicast packet identifier module (20).

15. The method as claimed in Claim 16, wherein the step of converting the multicast packets to Multimedia Access Control (MAC) layer unicast packets includes the step of converting the multicast packets to the MAC layer unicast packets based number of nodes subscribed to said multicast packets and using addresses including an MAC address of each of the nodes associated with the multicast packets, a destination hardware address and a destination Internet Protocol (IP) address.

16. The method as claimed in Claim 16, wherein the step of receiving and forwarding traffic from a first network includes the following steps:

i. receiving and checking a multicast subscription message based traffic from the second network by the backhaul module (10); adding an entry for a new multicast address into the multicast translation table (90) on the first network, and sending an adding notification for the new multicast address to a multicast subscription module (120) by using the multicast module (40), if the multicast subscription message is a request for a new multicast address that does not consist of a node;

sending a join multicast subscription message for the new multicast address to the first network through the backhaul module (10) by using the multicast subscription module (120); and

removing the entry of the multicast address from the multicast translation table (90), and sending a deleting notification for the multicast address to the multicast subscription module (120) by using the multicast module (40), if the multicast subscription message is a request to leave the multicast address; and sending a leave multicast subscription message to the first network through the backhaul module (10) by using the multicast subscription module (120).