Abstract: A preprocessing system includes a first port, where one end of the first port is coupled to a first switch, and the other end of the first port is suspended, where the first switch has a connecting end configured to couple to a first interface and is configured to connect a filter and the first interface, a second port configured to receive a first signal or a second signal, where the filter is configured to filter the first signal to obtain a first positioning signal and a second positioning signal, provide the first positioning signal for the first switch, and provide the second positioning signal for a second interface of a global navigation satellite system (GNSS) chip to adapt to a plurality of antenna configuration types and to achieve universality.

Abstract: Some embodiments provide a method for a first managed forwarding element operating within a first data compute node (DCN) that executes on a host machine. From the first DCN, the method receives a packet destined for a second DCN that is logically connected to the first DCN through a set of logical forwarding elements of a logical network. The method performs forwarding processing on the packet in order to (i) identify a particular logical forwarding element in the set of logical forwarding elements, a logical port of which is coupled to the second DCN, and (ii) identify a second managed forwarding element that implements the logical port of the particular logical forwarding element. The method forwards the packet to the second managed forwarding element.

Abstract: Some embodiments provide a method for a managed forwarding element (MFE) operating within a first data compute node (DCN) that executes on a first host machine. The MFE is for implementing a logical network that logically connects the first DCN to a plurality of other DCNs. At the MFE, the method receives several packets generated within the first DCN to be forwarded to a second DCN that is logically connected to the first DCN. The method determines whether the second DCN executes on the first host machine or on a second, different host machine. When the second DCN executes on the first host machine, the method stores the packets in a memory space of the first host machine that is shared between the first and second DCNs.

Abstract: Some embodiments provide a method for a managed forwarding element (MFE) operating within a first data compute node (DCN) that executes on a first host machine. The MFE is for implementing a logical network that logically connects the first DCN to a plurality of other DCNs. At the MFE, the method receives several packets generated within the first DCN to be forwarded to a second DCN that is logically connected to the first DCN. The method determines whether the second DCN executes on the first host machine or on a second, different host machine. When the second DCN executes on the first host machine, the method stores the packets in a memory space of the first host machine that is shared between the first and second DCNs.

Abstract: Some embodiments provide a method for a first managed forwarding element operating within a first data compute node (DCN) that executes on a host machine. From the first DCN, the method receives a packet destined for a second DCN that is logically connected to the first DCN through a set of logical forwarding elements of a logical network. The method performs forwarding processing on the packet in order to (i) identify a particular logical forwarding element in the set of logical forwarding elements, a logical port of which is coupled to the second DCN, and (ii) identify a second managed forwarding element that implements the logical port of the particular logical forwarding element. The method forwards the packet to the second managed forwarding element.