1. A label switching method, comprising:
when establishing a Passive Optical Network (PON)-based Label Switching Path (LSP) (PON-based LSP),
establishing a PON logical service transmission channel between an Optical Line Terminal (OLT) and an Optical Network Unit (ONU), and
according to an identifier (ID) of the PON logical service transmission channel as a PON label, updating a PON-based Forwarding Information Base (FIB) table on the ONU, and updating a PON-based Label Forwarding Information Base (LFIB) table on the OLT,
wherein the PON-based LFIB table records a forwarding relationship between an ingress port plus an ingress label and an egress port plus an egress label, and the PON-based FIB table records a forwarding relationship between the ingress port plus a destination address and the egress port plus the egress label; and
when a data packet arrives at the ONU,
forwarding, by the ONU, according to the PON-based FIB table on the ONU, the data packet to the OLT, wherein the forwarding the data packet to the OLT comprises: converting the data packet to a packet with the PON label, and forwarding the packet with the PON label to the OLT,
querying, by the OLT, the PON-based LFIB table according to an ingress PON interface as the ingress port and the ingress label of the received data packet, for performing label switching, and
transmitting the packet to a next hop node according to the egress port and the egress label after the label switching; or
when a data packet arrives at the OLT,
querying, by the OLT, the PON-based LFIB table according to the ingress port and a Multi-protocol Label Switching (MPLS) label as the ingress label of the data packet, for performing label switching,
transmitting the packet to the ONU according to an egress PON interface as the egress port and an egress PON label as the egress label, and
forwarding, by the ONU, the received packet with the PON label according to the PON-based FIB table.
2. The label switching method according to claim 1, wherein distribution of the PON label between the OLT and the ONU is implemented through an extended Label Distribution Protocol (LDP) or a Resource Reservation Protocol (RSVP); or implemented through an Optical Network Termination (ONT) Management Control Interface (OMCI) protocol or an Operation, Administration and Maintenance (OAM) protocol.
3. The label switching method according to claim 1, wherein the ingress label is the PON label or the MPLS label, the egress label is the MPLS label or the PON label, the PON label is a Gigabit Passive Optical Network (GPON) Encapsulation Method (GEM) port ID (GEM port ID) or a Logical Link ID (LLID), and the PON logical service transmission channel is a channel corresponding to the GEM port or the LLID.
4. The label switching method according to claim 2, wherein the ingress label is the PON label or the MPLS label, the egress label is the MPLS label or the PON label, the PON label is a Gigabit Passive Optical Network (GPON) Encapsulation Method (GEM) port ID (GEM port ID) or a Logical Link ID (LLID), and the PON logical service transmission channel is a channel corresponding to the GEM port or the LLID.
5. An Optical Line Terminal (OLT), comprising a control plane processing module and a data plane processing module, wherein
the control plane processing module is configured to establish a Passive Optical Network (PON) logical service transmission channel between the OLT and an Optical Network Unit (ONU), distribute a PON label, and generate a PON-based Label Forwarding Information Base (LFIB) table according to the PON label; and
the data plane processing module is configured to query the PON-based LFIB table according to an ingress port and an ingress label of a data packet received from a Multi-protocol Label Switching (MPLS) label switching domain to obtain a corresponding egress port and a corresponding egress label wherein the egress label is a PON label, perform label switching on the input data packet, remove MPLS packet header of the data packet, add a PON frame header to the data packet, wherein the PON frame header comprises the egress label, and output the data packet carrying the corresponding egress label from the corresponding egress port.
6. The OLT according to claim 5, wherein the control plane processing module comprises a PON-based Label Distribution Protocol (LDP) processing unit and a PON configuration unit, wherein
the PON-based LDP processing unit is configured to distribute the PON label, and generate the PON-based LFIB table according to the PON label; and
the PON configuration unit is configured to establish and maintain the PON logical service transmission channel.
7. The OLT according to claim 5, wherein the data plane processing module comprises a PON-based LFIB processing unit, a PON interface processing unit, and a network side interface processing unit, wherein
the PON-based LFIB processing unit is configured to store and maintain the PON-based LFIB table, and implement label switching and forwarding according to the PON-based LFIB table;
the PON interface processing unit is configured to implement a PON interface communication processing function; and
the network side interface processing unit is configured to implement a network side interface communication processing function.
8. The OLT according to claim 7, wherein the data plane processing module further comprises a PON-based Forwarding Information Base (FIB) processing unit, configured to store and maintain a PON-based FIB table, and implement label-based routing and forwarding according to the PON-based FIB table.
9. The OLT according to claim 5, wherein the control plane processing module comprises a PON admission control unit, a routing protocol processing unit, an Internet Protocol (IP) routing table processing unit, a PON-based Label Information Base (LIB) unit, and a path calculation unit,
the PON admission control unit is configured to implement PON interface bandwidth admission control, and trigger execution of a PON admission control through an LDP;
the routing protocol processing unit is configured to generate a PON-based routing table;
the IP routing table processing unit is configured to store and maintain the routing table;
the PON-based LIB unit is configured to store and maintain a PON-based LIB table, the PON-based LIB table being configured to assist the generating of the PON-based LFIB table or generating a PON-based FIB table and the PON-based LFIB table; and
the path calculation unit is configured to trigger establishment of a PON-based Label Switching Path (LSP).
10. The OLT according to claim 6, wherein the data packet is a Multi-protocol Label Switching (MPLS) packet or a PON frame, the ingress label is the PON label or the MPLS label, the egress label is the MPLS label or the PON label, the PON label is a Gigabit Passive Optical Network (GPON) Encapsulation Method (GEM) port identifier (GEM port ID) or a Logical Link ID (LLID), and the PON logical service transmission channel is a channel corresponding to the GEM port or the LLID.
11. The OLT according to claim 7, wherein the data packet is a Multi-protocol Label Switching (MPLS) packet or a PON frame, the ingress label is the PON label or the MPLS label, the egress label is the MPLS label or the PON label, the PON label is a Gigabit Passive Optical Network (GPON) Encapsulation Method (GEM) port identifier (GEM port ID) or a Logical Link ID (LLID), and the PON logical service transmission channel is a channel corresponding to the GEM port or the LLID.
12. The OLT according to claim 9, wherein the data packet is a Multi-protocol Label Switching (MPLS) packet or a PON frame, the ingress label is the PON label or the MPLS label, the egress label is the MPLS label or the PON label, the PON label is a Gigabit Passive Optical Network (GPON) Encapsulation Method (GEM) port identifier (GEM port ID) or a Logical Link ID (LLID), and the PON logical service transmission channel is a channel corresponding to the GEM port or the LLID.
13. The OLT according to claim 6, wherein the PON-based LDP processing unit is further configured to interact with the PON configuration unit, so as to implement interworking between an Optical Network Termination (ONT) Management Control Interface (OMCI) and an LDP or a Resource Reservation Protocol (RSVP), or implement interworking between an Operation, Administration and Maintenance (OAM) protocol and the LDP or the RSVP.
14. An Optical Network Unit (ONU), wherein an Optical Line Terminal (OLT) comprises a control plane processing module and a data plane processing module, wherein
the control plane processing module is configured to cooperate with the ONU to establish a Passive Optical Network (PON) logical service transmission channel between the OLT and the ONU, distribute a PON label, and generate a PON-based Forwarding Information Base (FIB) table according to the PON label, wherein the PON-based FIB table comprises a forwarding relationship between an ingress port plus a destination address and an egress port plus a PON label; and
the data plane processing module is configured to query the PON-based FIB table according to a destination address of a data packet to obtain a corresponding egress port and a corresponding PON label, add a PON frame header to the data packet, wherein the PON frame header comprises the PON label, and output the data packet from the egress port for performing forwarding.
15. The ONU according to claim 14, wherein the control plane processing module comprises a PON-based Label Distribution Protocol (LDP) processing unit and a PON configuration unit, wherein
the PON-based LDP processing unit is configured to distribute the PON label, and generate the PON-based FIB table according to the PON label; and
the PON configuration unit is configured to establish and maintain the PON logical service transmission channel.
16. The ONU according to claim 15, wherein the data plane processing module comprises a PON-based FIB processing unit, a PON interface processing unit, and a network side interface processing unit, wherein
the PON-based FIB processing unit is configured to store and maintain the PON-based FIB table, and implement label-based routing and forwarding according to the PON-based FIB table;
the PON interface processing unit is configured to implement a PON interface communication processing function; and
the network side interface processing unit is configured to implement a network side interface communication processing function.
17. The ONU according to claim 14, wherein the data packet comprises an Asynchronous Transfer Mode (ATM) cell, a Time Division Multiplexing (TDM) time-slot, an Ethernet (ETH) frame, or an Internet Protocol (IP) packet, the ingress label is the PON label or a Multi-protocol Label Switching (MPLS) label, the egress label is the MPLS label or the PON label, the PON label is a Gigabit Passive Optical Network (GPON) Encapsulation Method (GEM) port identifier (GEM port ID) or a Logical Link ID (LLID), and the PON logical service transmission channel is a channel corresponding to the GEM port or the LLID.
18. The ONU according to claim 15, wherein the data packet comprises an Asynchronous Transfer Mode (ATM) cell, a Time Division Multiplexing (TDM) time-slot, an Ethernet (ETH) frame, or an Internet Protocol (IP) packet, the ingress label is the PON label or a Multi-protocol Label Switching (MPLS) label, the egress label is the MPLS label or the PON label, the PON label is a Gigabit Passive Optical Network (GPON) Encapsulation Method (GEM) port identifier (GEM port ID) or a Logical Link ID (LLID), and the PON logical service transmission channel is a channel corresponding to the GEM port or the LLID.
19. The ONU according to claim 16, wherein the data packet comprises an Asynchronous Transfer Mode (ATM) cell, a Time Division Multiplexing (TDM) time-slot, an Ethernet (ETH) frame, or an Internet Protocol (IP) packet, the ingress label is the PON label or a Multi-protocol Label Switching (MPLS) label, the egress label is the MPLS label or the PON label, the PON label is a Gigabit Passive Optical Network (GPON) Encapsulation Method (GEM) port identifier (GEM port ID) or a Logical Link ID (LLID), and the PON logical service transmission channel is a channel corresponding to the GEM port or the LLID.
20. The ONU according to claim 15, wherein the control plane processing module further comprises a routing protocol processing unit, an IP routing table processing unit, a PON-based Label Information Base (LIB) unit, and a path calculation unit, wherein
the routing protocol processing unit is configured to generate a PON-based routing table;
the IP routing table processing unit is configured to store and maintain the PON-based routing table;
the PON-based LIB unit is configured to store and maintain a PON-based LIB table, the PON-based LIB table being configured to assist generating the PON-based FIB table; and
the path calculation unit is configured to trigger establishment of a PON-based Label Switching Path (LSP).
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of qualifying Niobium andor other super conducting materials for the reliable fabrication of SCRF cavities, which will invariably deliver high accelerating fields comprising:
identification of the best superconducting lower critical field (HCC1) based on subjecting a sample of the superconducting material selectively to mechanical stress, annealing at various temperatures, various chemical treatments, post-chemical treatment bakingannealing; and
identification of the best possible thermal conductivity of the material at said best superconducting lower critical field (HC1) to thereby qualify the superconducting material for the reliable fabrication of SCRF cavities adapted to deliver high accelerating fields.
2. A method of qualifying niobium and other super conducting materials according to claim 1, comprising the steps of:
(i) measuring the HC1 and thermal conductivity on a small sample of the said superconducting material obtained from a pure but untreated ingot which could be anyone of Niobium, MgB2,Nb3Sn,Nb3Al and Mo\u2014Re alloys;
(ii) subjecting the sample to mechanical stress and noting the variationseffects thereof, if any, in the HC1;
(iii) annealing the sample at various temperatures and noting the changes in the HC1 and determine if possible manner of improving the HC1;
(iv) subjecting the sample to various chemical treatments and noting the variations in the HC1;
(v) subjecting the chemically treated sample to bakingannealing and noting the variations in the HC1 and improving the same if possible;
(vi) measuring the thermal conductivity with the best identified HC1 and improving the thermal conductivity with suitable heat treatment if possible without degrading the HC1.
3. A method of qualifying niobium and other super conducting materials according to claim 2, wherein the various steps are repeated for sample from the top, bottom and middle of the mother ingot for determine the best qualifying procedure for the superconducting material.
4. A method of qualifying niobium and other super conducting materials according to claim 2, wherein said step of chemical treatment of the sample comprises selectively chemical treatments including BCP or EP.
5. A method of qualifying niobium and other super conducting materials according to claim 2, wherein the said HC1 is estimated based on determination of the \u201cfirst penetration\u201d of magnetic field into the superconducting niobium sample.
6. A method of qualifying niobium and other super conducting materials according to claim 5, comprising measuring the isothermal field dependent magnetization of superconducting sample at various temperatures below the superconducting transition temperature;
establishing the magnetic field at which the deviation from linearity starts in the isothermal magnetization versus magnetic field plot for an initial estimate of the HC1; and
estimation for more precise value of HC1 which is the field value at which \u221aMrem=0 in the isothermal \u221aMrem versus magnetic field plot wherein \u221aMrem stands for the remnant magnetization (or trapped magnetic field) in the sample after a field excursion in an applied magnetic field H.
7. A method of qualifying niobium and other super conducting materials according to claim 2, wherein
in said step (iii) a small sample of niobium is heat treated at suitable temperatures for the strain recovery in the sample but avoiding nucleation and grain growth;
in said step (iv) for the smoothening of the surface of the niobium sample involving buffer chemical polishing or electro polishing, each surface treatment is followed by the said estimation of the HC1;
in said step (v) in carrying out the post chemical-treatment annealing, the small sample of Niobium is heat treated at suitable temperatures for degassing of Hydrogen, which is then followed by said estimation of the HC1;
in said step (vi) the thermal conductivity is measured in zero and applied magnetic fields up to HC1 at 2K and 4.5K.
8. A method of qualifying niobium and other super conducting materials according to claim 7, wherein the said step of measuring thermal conductivity is repeated after heating at various temperatures and the optimal heat treatment for obtaining the best thermal conductivity is established.
9. A method of qualifying niobium and other super conducting materials according to claim 2, wherein in the instance the said estimated HC1 is found to be smaller than that obtained after said step (v), the steps (a), (viz. of measuring the thermal conductivity in zero and applied magnetic fields upto HC1 at 2K and 4.5K), (b) (viz. of measuring thermal conductivity after heating at various temperatures and the optimal heat treatment for obtaining the best thermal conductivity is established) and (c) (viz. of measuring the HC1 of the sample with highest thermal conductivity) are repeated until the sample has the best combination of HC1 and thermal conductivity.
10. A method of qualifying niobium and other super conducting materials according to claim 3, wherein for each said samples from the top, bottom and middle part of the ingot are subjected to the same said steps such as to optimize the chemical, mechanical and thermal treatment directed to achieve the best HC1 and thermal conductivity values.
11. A method targeted towards SC-RF cavity fabrication based on Niobium or other superconductor materials involving the step of qualifying Niobium andor other superconducting materials as claimed in claim 1 for desired SC-RF cavity fabrication invariably delivering high accelerating gradients.