Exinda EXNV-10063, Administration Manual

Page: 467 / 623

Exinda Network Orchestrator 4 Settings | 467
Appliances that can participate in accelerated communications are discovered by detecting extra information in the flow
that is required during acceleration of a flow. The appliance adds the following information to the TCP option of SYN,
SYN-ACK, and the first ACK packets of each new connection:
Source Appliance ID
Destination Appliance ID
Acceleration Module Map
Optionally an IP address corresponding to one of the appliances can be sent. In addition to this, each appliance must
keep a list of the host IP/appliance ID pairs, which indicates which Exinda appliance terminates the acceleration for
conversations with a given host IP.
Discovery Process
The connection discovery process is as follows:
1. When an appliance receives a packet SYN from a client:
It adds the client IP to its local list. E.g., adding 192.168.0.10 to the Ex1 local list.
It adds the auto-discovery option to the packet, filling out the source details. E.g., adding Ex1 as the source of
the SYN when leaving Ex1.
If the server exists in the appliance remote list, then the destination field is filled out with the appliance
details, otherwise the destination is left blank.
2. When an appliance receives a SYN packet containing the auto-discovery option:
It records the client IP address and source appliance ID to its remote list. E.g., adding 192.168.0.10, Ex1 to the
local lists of Ex2 and Ex3.
It fills out the destination details and forwards the packet on. E.g., adding Ex2 as the destination of the SYN
when leaving Ex2 and replacing the destination of the SYN with Ex3 when leaving Ex3.