Method and apparatus for controlling information element switch

1. A method for controlling information element switch, comprising:

determining, via a switch board, that a link request information element from each of at least one ingress line card is received, wherein each link request information element carries request time stamp information, an egress line card identity and address information of corresponding ingress line card that transmits the link request information element;

performing, via the switch board, a link allocation according to each request time stamp information, wherein the link to be allocated is a link connecting the switch board with each egress line card, and wherein the switch board is configured to allocate the available link to the ingress line card that applied for a link early based on the request time stamp information; and

wherein the step of performing, via the switch board, a link allocation comprises:

extracting, via the switch board, the request time stamp information from each link request information element, comparing a size of the each request time stamp information, and selecting an ingress line card with minimum request time stamp information as a first line card waiting for allocation,

selecting one ingress line card as the first line card waiting for allocation from ingress line cards to which the multiple values correspond, according to the address information of the ingress line card, when multiple values of the each request time stamp information are the same, and the multiple values are less than other request time stamp information except the multiple values, and

determining, via the switch board, whether an egress line card to which the egress line card identity corresponds is in an idle state, and if yes, allocating a link to which the egress line card identity corresponds to the first line card waiting for allocation; and

transmitting, via each ingress line card, a data information element according to a result of the link allocation.

2. The method according to claim 1 , wherein after determining, via the switch board, whether the egress line card to which the egress line card identity corresponds is in the idle state, the method further comprises: if a result of determining by the switch board is no, determining that the egress line card to which the egress line card identity corresponds is in an allocated state, and notifying, via the switch board, the first line card waiting for allocation to re-request for link.

3. The method according to claim 1 , wherein both the link request information element and the data information element carry a type identity; and before the switch board determining that the link request information element from the each ingress line card is received, the method further comprises: the switch board determining the type of the received information element according to the type identity; and if the information element is the data information element, the switch board forwarding the data information element to corresponding egress line card.

4. The method according to claim 1 , wherein after the switch board performing the link allocation according to the each request time stamp information, the method further comprises: changing the state of the egress line card of the allocated link to an allocated state; and

after the each ingress line card transmitting the data information element according to the result of the link allocation, the method further comprises:

notifying the switch board to release a corresponding link; and after receiving the notification, the switch board changing the state of the egress line card of the corresponding link to an idle state.

5. The method according to claim 1 , wherein after determining, via the switch board, whether the egress line card to which the egress line card identity corresponds is in the idle state, the method further comprises: if a result of determining by the switch board is no, determining that the egress line card to which the egress line card identity corresponds is in an allocated state, and notifying, via the switch board, the first line card waiting for allocation to re-request for link.

6. An apparatus for controlling information element switch, comprising an ingress line card, a switch board and an egress line card, wherein the ingress line card comprises:

a time stamp marking and transmitting module configured to transmit a link request information element to the switch board, wherein the link request information element carries request time stamp information;

a data information element transmitting module configured to transmit a data information element according to a result of link allocation of the switch board; and

the switch board configured to receive the link request information element from each of at least one ingress line card and to perform the link allocation according to each request time stamp information, wherein the link is a link connecting the switch board with each of at least one egress line card, and wherein the switch board is configured to allocate the available link to the ingress line card which applied for a link early based on the request time stamp information, and wherein the switch board comprises:

a time stamp information extracting module, configured to extract the request time stamp information from each received link request information element;

a time stamp comparing module, configured to compare size of each request time stamp information extracted by the time stamp information extracting module, and to select an ingress line card with minimum request time stamp information as a first line card waiting for allocation, wherein the time stamp comparing module further comprises: a line card selecting unit, configured to, when multiple values in the request time stamp information of the each ingress line card are the same, and the multiple values are less than other request time stamp information except the multiple values, select one ingress line card as the first line card waiting for allocation from ingress line cards to which the multiple request time stamp information values correspond according to address information of the ingress line card carried in the link request information element; and

a link allocating module, configured to determine whether an egress line card to which an egress line card identity corresponds is in an idle state according to the egress line card identity carried in the link request information element of the first line card waiting for allocation, and if yes, to allocate a link to which the egress line card identity corresponds to the first line card waiting for allocation.

7. The apparatus according to claim 6 , wherein the switch board further comprises:

an information element separating module, configured to, after receiving an information element carrying a type identity, if it is determined that the received information element is the link request information element according to the type identity, transmit the link request information element to the time stamp information extracting module, and if it is determined that the received information element is the data information element according to the type identity, transmit the data information element to a data information element processing module; and

the data information element processing module, configured to forward the data information element to corresponding egress line card.