Acquiring addresses in an input/output system
First Claim
1. In a computer I/O system including a plurality of link-level facilities and a dynamic switch having a plurality of ports, each link-level facility being attached to an individual one of said ports, a mechanism for assigning a unique link address to each of said link-level facilities wherein each link-level facility comprises:
- frame generator means for sending an acquire link address (ALA) frame to the dynamic switch via the port to which said link-level facility is attached;
frame recognition means for receiving a response frame from said dynamic switch via said attached port, said frame recognition means including means for recognizing a response frame from said dynamic switch is response to said ALA frame, said response frame including an assigned link address;
link-address storing means for storing the assigned link address from said response frame as its unique link address; and
wherein said plurality of link-level facilities includes a channel link-level facility and a control-unit link-level facility, said channel link-level facility being connected to said control-unit link-level facility by a dedicated static connection through said dynamic switch; and
said channel link-level facility further comprises;
reject frame recognition means in its frame recognition means for recognizing a link-level reject frame with an ALA error reason code; and
address assigning means for assigning a unique link address to said channel link-level facility and said control-unit link-level facility responsive to said reject frame recognition means.
1 Assignment
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Accused Products
Abstract
In a computer I/O system including a plurality of link-level facilities and a dynamic switch having a plurality of ports, each link-level facility being attached to an individual one of the ports, a mechanism and method for assigning a unique link level address to each of the link-level facilities. As each of the link-level facilities comes on line, it sends an acquire link address (ALA) frame and waits for a response (ACK) frame. The ALA frame may be addressed to a general to-whom-it-may-concern address and have a source address of who-am-I. Only a dynamic switch normally assigns link addresses. When receiving an ALA frame, the dynamic switch returns an ACK frame having a unique link address assigned to the sender of the ALA frame. Provision is made for determining if there is a dynamic switch present, or, if the link-level facilities are connected together by a static connection through the dynamic switch, for the link-level facility of a channel to assign the unique link addresses.
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Citations
8 Claims
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1. In a computer I/O system including a plurality of link-level facilities and a dynamic switch having a plurality of ports, each link-level facility being attached to an individual one of said ports, a mechanism for assigning a unique link address to each of said link-level facilities wherein each link-level facility comprises:
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frame generator means for sending an acquire link address (ALA) frame to the dynamic switch via the port to which said link-level facility is attached; frame recognition means for receiving a response frame from said dynamic switch via said attached port, said frame recognition means including means for recognizing a response frame from said dynamic switch is response to said ALA frame, said response frame including an assigned link address; link-address storing means for storing the assigned link address from said response frame as its unique link address; and wherein said plurality of link-level facilities includes a channel link-level facility and a control-unit link-level facility, said channel link-level facility being connected to said control-unit link-level facility by a dedicated static connection through said dynamic switch; and said channel link-level facility further comprises; reject frame recognition means in its frame recognition means for recognizing a link-level reject frame with an ALA error reason code; and address assigning means for assigning a unique link address to said channel link-level facility and said control-unit link-level facility responsive to said reject frame recognition means. - View Dependent Claims (2, 3, 4)
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5. In a computer I/O system including a plurality of link-level facilities and a dynamic switch having a plurality of ports, each link-level facility being attached to an individual one of said ports, said plurality of link-level facilities including a channel link-level facility and a control-unit link-level facility, said channel link-level facility being connected to said control-unit link-level facility by a dedicated static connection through said dynamic switch, a method for assigning a unique link address to each of said link-level facilities comprising:
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sending an acquire link address (ALA) frame to the dynamic switch from an ALA frame generator in one of said link-level facilities via the port to which said one link-level facility is attached; assigning by an assigning means in said dynamic switch, an assigned unique link address to identify said one link-level facility; sending said assigned unique link address in a response frame from said dynamic switch to said one link-level facility; receiving at said one link-level facility, said response frame from said dynamic switch via said attached port in response to said ALA frame, said response frame including said assigned unique link address; storing in said one link-level facility, the assigned unique link address from said response frame as said one link-level facility'"'"'s unique link address; recognizing at said channel link-level facility, an ALA frame; assigning by said channel link-level facility, a unique link address to said control-unit link-level facility responsive to an ALA frame recognition means in said channel link-level facility for recognizing ALA frames; and sending said response frame from said channel link-level facility to said control-unit link-level facility through said dynamic switch, said response frame including said unique link address. - View Dependent Claims (6, 7, 8)
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Specification