Dynamic Transition From Tcp To Smc-R; D.2.3 Single Root I/O Virtualization - IBM z13s Technical Manual

data exchanged
using RDMA
Figure D-2 Dynamic transition from TCP to SMC-R
The hybrid model of SMC-R uses these key existing attributes:
It follows the standard TCP/IP connection setup.
The hybrid model switches to RDMA (SMC-R) dynamically.
The TCP connection remains active (idle) and is used to control the SMC-R connection.
The hybrid model preserves the following critical operational and network management
TCP/IP features:
– Minimal (or zero) IP topology changes
– Compatibility with TCP connection-level load balancers
– Preservation of the existing IP security model, such as IP filters, policies, virtual LANs
(VLANs), and Secure Sockets Layer (SSL)
– Minimal network administration and management changes
Host application software is not required to change, so all host application workloads can
benefit immediately.

D.2.3 Single Root I/O Virtualization

SR-IOV is a technology that is designed to provide the capability to share the adapter
between up to 31 LPARs. SR-IOV is also designed to provide isolation of virtual functions
within the Peripheral Component Interconnect Express (PCIe) 10GbE RoCE Express
adapter. For example, one LPAR cannot cause errors visible to other virtual functions or other
LPARs. Each operating system LPAR has its own application queue in its own memory space.
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IBM z13s Technical Guide
SMC-R enabled platform
Middleware/Application
Sockets
TCP
SMC-R
IP
Interface
RNIC ETH
TCP connection establishment over IP
TCP syn flows (TCP Option SMCR)
Dynamic (in-line) negotiation for SMC-R is initiated by presence of TCP Option (SMCR)
TCP connection transitions to SMC-R allowing application data to be exchanged using RDMA
SMC-R enabled platform
Middleware/Application
TCP
IP
Interface
RDMA Network RoCE (CEE)
IP Network (Ethernet)
Sockets
SMC-R
ETH
RNIC
data exchanged
using RDMA