Abstract: Stateful failover redundancy support is provided for network address translation (NAT). A master NAT device is backed-up with at least one back-up NAT device. Existing sessions are synchronized between the two NAT devices, such as via a dedicated link between them. In the event of a failover where the master NAT device is unable to perform its NAT functions, ownership of Internet protocol (IP) addresses is transferred from the master NAT device to the back-up NAT device. The back-up NAT device, which is now owner of the IP addresses, assumes the NAT functionality associated with these IP addresses and continues the existing sessions, as well as processing new sessions.

Abstract: Long distance cloud migration (LDCM) to overcome the limitations faced by the cloud migration techniques over long distance, high speed WAN infrastructures. LDCM overcomes the negative effects of existing TCP/IP mechanisms on the efficient use of available bandwidth. LDCM also acts as an acceleration engine to optimize various hypervisor, storage and security applications.

Abstract: A smoothing algorithm for round trip time (RTT) measurements is provided to a network device to effectively deal with variations or other potential anomalies that may occur in RTT measurements. The algorithm involves: first determining what should be considered a very high or a very small value for a RTT sample. If a new RTT sample is in an acceptable range, then the network device performs a relatively basic smoothing. If the new RTT sample is much higher than a current RTT value, then the network device ignores the value of this RTT sample a few times. If the network device still detects this large value after ignoring that value for some time, then the network device factors this value into the current RTT value using an additive increase. Similarly, if the value of the new RTT sample is much lower than current RTT value, the network device ignores the value of the new RTT sample a few times.

Abstract: A hypervisor preferably provides VM identification, priority and LUN/LBA range information to the HBA when a VM is created. Alternatively, the HBA can determine that a LUN/LBA range is new and request VM identity, priority and LUN/LBA range from the hypervisor. The HBA creates a table containing the VM identification, priority and LUN/LBA range. The HBA then detects operations directed to the LUN/LBA range and does a lookup to determine VM identification and priority. VM identification and priority are then mapped into a field in a frame using a unique identifier. The unique identifier can either be placed using reserved bits on the existing Fibre Channel (FC) header or can use bits in an additional header, such as a modified IFR header.

Abstract: A key identifier for an encryption key repository is stored with customer data on a logical device. When the customer data is compressible, the key identifier is stored in space freed by compressing the customer data. When the customer data is not compressible, a portion of the customer data is copied to a key record in the key repository identified by the key identifier, and the key identifier overwrites the copied customer data.

Abstract: One embodiment of the present invention provides a switch system. The switch includes one or more ports on the switch configured to transmit packets encapsulated based on a first protocol. The switch further includes a control mechanism. During operation, the control mechanism forms a logical switch based on a second protocol, receives an automatically assigned identifier for the logical switch without requiring manual configuration of the identifier, and joins a virtual cluster switch.

Abstract: A management station which manages the encryption devices in a SAN to set up encrypted LUNs. In setting up the encryption, the source and target ports are identified, along with the target LUN. LUN serial numbers used to identify unique LUNs. As paths to a given LUN are defined, the management station compares the path to existing paths and provides an indication if there is a mismatch in the encryption policies or keys being applied to the LUN over the various paths. This allows the administrator to readily identify when there is a problem with the paths to an encrypted LUN and then take steps to cure the problem. By determining the paths and then comparing them, the management station greatly simplifies setting up multipath I/O to an encrypted LUN or access by multiple hosts to an encrypted LUN.

Abstract: A network device is adaptively configured to compress an output data stream, responsive to congestion in the network. The network device receives indications of network congestion from another network device. Upon receipt of a congestion indication, the network device can adapt the compression technique to attempt to achieve more or less compression, depending on whether the congestion indication indicates more or less congestion. By adapting the compression to the level of network congestion, end-to-end latency of the network can potentially be decreased.

Abstract: One embodiment of the present invention provides a system that facilitates transmission buffer under-run protection. During operation, the system stores bits of a data frame in a transmission buffer associated with an output port. The system also monitors the state of the transmission buffer and commences transmission of the data frame to the output port prior to complete reception of the data frame in the transmission buffer. The system further determines that the amount of data stored in the transmission buffer is below a predetermined threshold and inserts a number of predetermined unique bit sequences after the partially transmitted data frame, thereby allowing a receiving device to temporarily suspend reception of the data frame and resume reception at a later time without dropping the data frame.

Abstract: One embodiment of the present invention provides a switch. The switch includes a management mechanism and a configuration mechanism. During operation, the management mechanism is configured to operate the switch in conjunction with the partner switch as a single logical switch. The configuration mechanism is configured to assign a virtual switch identifier to the logical switch.

Abstract: An IP gateway device establishes distinct TCP sessions within a single FCIP tunnel, each TCP session being designated for a different priority of service (e.g., high, medium, low), plus a control stream. Each TCP session has its own TCP stack and its own settings for VLAN Tagging (IEEE 802.1Q), quality of service (IEEE 802.1P) and Differentiated Services Code Point (DSCP). By distributing data streams assigned to different priorities of service into different TCP sessions within the FCIP tunnel, an IP gateway device can preserve the distinctions between the data stream priorities while the data traffic is within the IP network. By further distributing the data streams between different circuits and trunks by use of multiple circuits, failover and load balancing can occur within the FCIP tunnels.

Abstract: One embodiment of the present invention provides a switch that includes a transmission mechanism configured to transmit frames stored in a queue, and a queue management mechanism configured to store frames associated with the queue in a number of sub-queues which allow frames in different sub-queues to be retrieved independently, thereby facilitating parallel processing of the frames stored in the sub-queues.

Abstract: One embodiment of the present invention provides a system that facilitates automatic adjustment of logical channels in a Fiber Channel (FC) network. During operation, the system receives FC data frames. A respective data frame is associated with a logical channel. The bandwidth on an FC link can be allocated into a plurality of logical channels, and a respective logical channel is associated with a dedicated buffer and can transport a plurality of data flows with data frames of variable length. The system then identifies a slow data flow in a first logical channel. Next, the system assigns the slow data flow to a second logical channel, thereby preventing the slow data flow from slowing down other data flows in the first logical channel. The system subsequently forwards the data frames in the slow data flow on the second logical channel onto an outgoing link.

Abstract: A cooling device for rack mount equipment comprises an extensible side duct, open on its inner and rear-facing sides which redirects warm exhaust air exiting vents in the side of a chassis towards the rear of an enclosure holding the chassis. An apparatus incorporating the cooling device may be installed in a rack with the extensible side duct in a retracted position. The extensible side duct may extend under the influence of air pressure, forming a plenum in fluid communication with the interior of a chassis on which it is mounted such that warm air exiting the chassis is collected in the plenum formed by the extensible side duct and directed out towards the rear of the chassis. Use of the apparatus permits conventional front-to-back cooling airflow patterns to be maintained even with chassis having side exhaust vents.

Abstract: One embodiment provides a system that facilitates bandwidth-profile enforcement. During operation, the system indicates a packet's compliance with a bandwidth profile based at least on available high-compliance tokens and medium-compliance tokens. The system further converts, within different classes of service (CoSs), an overflow high-compliance token to a medium-compliance token, in a top-down or bottom-up fashion with respect to different CoS priorities.

Abstract: A hypervisor preferably provides VM identification, priority and LUN/LBA range information to the HBA when a VM is created. Alternatively, the HBA can determine that a LUN/LBA range is new and request VM identity, priority and LUN/LBA range from the hypervisor. The HBA creates a table containing the VM identification, priority and LUN/LBA range. The HBA then detects operations directed to the LUN/LBA range and does a lookup to determine VM identification and priority. VM identification and priority are then mapped into a field in a frame using a unique identifier. The unique identifier can either be placed using reserved bits on the existing Fiber Channel (FC) header or can use bits in an additional header, such as a modified IFR header.

Abstract: Methods, devices and systems for improved zone merge operations are disclosed. Two connected switches are arbitrated as an initiator and a receiver. The merge operation is initiated only by the initiator on an initiator/receiver inter-switch link. The initiator may initiate a merge request and the receiver may perform the computation of the difference between the old and the new zone. Either the whole configuration or only the differences are communicated between the switches. The merges may be done on a connected switch basis, not on a connected port basis. Only the principal ports in the principal inter-switch-link perform the merge operation. All the remaining ports, i.e. the non-principal ports, adopt the merge result of the principal ports. The zone information may also be cached on each switch such that merge calculations need not be performed again when a merge operation with the same configuration occurs in the future.

Abstract: One embodiment of the present invention provides a system that facilitates quality of service (QoS) in a Fiber Channel (FC) host bus adaptor (HBA). In this system the bandwidth on an FC link between the HBA and the FC switch can be allocated into a plurality of logical channels, and a respective logical channel can transport data frames of variable length. Furthermore, a respective logical channel is associated with a dedicated buffer. During operation, the HBA communicates to an FC switch the HBA's capability of receiving or sending a data flow over a logical channel that couples the HBA to the FC switch. The HBA further receives logical-channel allocation information from the FC switch. Furthermore, the HBA associates data frames with a logical channel and transmits data frames to the FC switch on the corresponding logical channel.

Abstract: Systems for hardware-accelerated lossless data compression are described. At least some embodiments include data compression apparatus that includes a plurality of hash memories each associated with a different lane of a plurality of lanes (each lane including data bytes of a data unit being received by the compression apparatus), an array including array elements each including a plurality of validity bits (each validity bit within an array element corresponding to a different lane of the plurality of lanes), control logic that initiates a read of a hash memory entry if a corresponding validity bit indicates that said entry is valid, and an encoder that compresses at least the data bytes for the lane associated with the hash memory comprising the valid entry if said valid entry comprises data that matches the lane data bytes.

Abstract: A system and method for load balancing session initiation protocol (SIP) traffic based on bridging and tracking transactions and connections between frontend and backend devices. The method includes receiving a SIP message and parsing a header of the SIP message. The parsing may include selecting a transaction identifier. The method further includes accessing a transaction table based on the transaction identifier and selecting a connection for forwarding the SIP message. The SIP message is then forwarded by the selected connection.