Traffic separation. In the interests of safety Owners will recommend that the Master is to observe the recommendations as to traffic separation and routing as issued from time to time by the I.M.O. or as promulgated by the state of the flag of the vessel, or the state in which the effective management of the vessel is exercised. Financial
Traffic separation. For traffic separation we must take into account that a message must be moved to the extra virtual network only if this message will go through a congested output port. In order to know which destination nodes will pass through a congested port we implement a small logic block. The block has as input the row and column of the switch (assuming a 2D mesh) and the output port (N, E, W, S) that is congested. The block assumes the use of the XY routing algorithm. From this, it is straightforward to deduce the end nodes that are reached through the congested port. The resulting vector bit is ORed with the vector bit used at the end nodes for identifying congested end nodes (one bit per node). This vector bit is the one used in BAHIA named burstiness bitmap. A destination is assumed to be congested if the path to reach the destination passes through one (or more) congested points. For instance, for a E (east) port congested in a switch, only the end nodes in the same row but at the left of the congested switch will set the bit to destinations located at the right side of the congested port. Figure 13 shows two examples of different output ports congested and the end nodes that detect some end nodes as congested. Figure 13: BAHIA-2 examples of congested destinations (XY routing assumed). 5 OCRL The OCRL mechanism is an injection throttling mechanism where the switches notify the sources to adjust the traffic rate in order to remove the congestion present in the network. It is compatible with both wormhole and virtual cut through switching, and is composed of three basic elements (although congestion detection is easiest with the large buffers of virtual cut through switching): • Every input buffer at each switch has two control thresholds in order to detect the presence and the absence of congestion. • Notification packets are delivered through a control network that matches the current data network topology, which is a 2-D mesh. • Every processing node implements a congestion table to keep track of the possible destinations affected by the congested spots in the network.
Traffic separation. The second important aspect in designing shared backhaul solution is the traffic separation between the operators. Appropriate solution should enable application of different QoS policies to different traffic flows independently for each operator. The solution that enables logical separation of physical links is VLAN marking [8]. In VLAN approach flows of different operators are assigned to different VLANs and packets of each flow are marked with corresponding VLAN id. Each operator has at least one VLAN id, a number of VLANs can be used by one operator to separate also different logical interfaces.
Traffic separation. (a) Median barriers will be provided where the median width (between edge of traffic lanes) is less than 11 metres. Adequate sight distance will be provided.
Traffic separation. The SEN backbone shall provide logical traffic separation/segmentation for individual SEN participants. Segmentation on the backbone shall be provided for each SEN participant, based on last mile connections to the backbone. The SEN backbone shall also provide segmentation for isolation of an operations, administration, and management (OAM) network. The proposed method for segmentation on the SEN backbone shall be fully explained in the RFP response. The response shall include both a technical description and supporting rationale for using the proposed method. This shall consider technical, operational, and financial benefits relative to alternative approaches.
Traffic separation. As a first step every node implements a bitmap of as many bits as nodes exist in the network (burstiness bitmap). Each bit corresponds to a node in the network as seen in Figure 11. When a node receives a traffic burst this node will notify it to all nodes through its BNN wire. The rest of nodes will detect a high value in the BNN wire that corresponds to this node. When this occurs, every node will set to one the corresponding bit of the burstiness bitmap. At allocation stage, all messages are queued into the default virtual network. Nevertheless, at injection time, every message is checked for its destination. In case the packet to be injected is destined to an affected node according to the burstiness bitmap, this message will not be injected. Figure 11: Flow followed by messages in an end node Instead, this message will be transferred to the extra virtual network. Obviously, packets destined to a node with its burstiness bit reset, will be injected from the default VN and will be forwarded through the network using the default VN. In Figure 11 we can see an example where the sender node has messages queued for node 1, 5 and 6 in the default virtual network. Currently the sender node is about to inject a message destined to end node 5. As can be seen in the burstiness bitmap, node 5 previously notified was receiving bursty traffic, so messages destined to node 5 must be reallocated to the extra virtual network. Just before injecting, the arbiter of the sender node checks the burstiness bitmap and transfers the messages to the extra virtual network for a later injection.
