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Reliable High-Performance Protocols...
>TCP : designed for Internet – hides long latencies, retries.
>UDP : not reliable, RUDP doable but not in kernel.
>DCCP: Datagram Congestion Control Protocol ,
didn't exist at the time, still early development.
>SCTP: (Stream Control) close but connection-oriented and
focused on internet transport.
>TIPC: designed for LAN and Telco/Embedded Market.
(目前有vxWorks和linux版本) HomePage http://tipc.sourceforge.net/
端口的表示 port ID
{Z.C.N:ref}
The port ID is assigned
automatically by TIPC when the port is created, and consists of the 32-bit
network address of the port's node and a 32-bit reference value. The
reference value is guaranteed to be unique on a per-node basis and will not
be reused for a long time once the port ceases to exist.
因为port ID是port创建时自动分配的,为了方便使用,tipc提供了port naming
机制,使我们可以将服务端口关联到一个指定的数值(port name)上 (bind)
port naming 只支持 server port
(Port names and name sequences are designed for use by server ports. TIPC
does not allow a named sever port to initiate a connection (as if it were a
client port), nor does it allow the assignment of names to a connected client
port (as if it were a server port).)
port name组成 {type,instance} (用 type instance 两元组关联一到多个服务端口)
type 域0-63预留,编程时不要使用;
同一个name可以绑定多个port,也可以一个port绑定多个name
port name sequence 表示一个名字区间/序列 (表示一个服务类型的一个端口序列/区间,适于多播等应用
{type,lower bound,upper bound}
Name Subscriptions
--------------------------
TIPC provides a network topology service that applications can use to receive
information about what port names exist within the application's network zone.
提供网络拓扑(查询/订阅)服务,可以查询/订阅 服务的地址,状态事件,,
An application accesses the topology service by opening a message-based
connection to port name {1,1} and then sending "subscription" messages to the
topology service that indicate the port names of interest to the application;
in return, the topology service sends "event" messages to the application when
these names are published or withdrawn by ports within the network.
Applications are allowed to have multiple subscriptions active at the same
time; issuing a new subscription does not affect any existing subscription.
当消息发送的目的地不是port ID,而是port name时就需要把这个name转换
为对应的port ID,这个查询的过程对app是透明的,,
1.5.2 Source Routing
----------------------------
Once a message has been created, TIPC then determines what node the message
should be sent to. If the specified destination address is a port ID, the
destination node is pre-determined; if the address is a port name, TIPC performs
a name table lookup to select a port (see 1.4.1 above), and then uses the node
associated with that port. The message is then passed to a link for off-node
transmission (see 1.5.3 below) or is handed off to the destination port directly
if it is on the same node as the sender (see 1.5.5 below).
Problems that can arise during the source routine phase of message delivery:
- No matching port can be located during a name table lookup when sending by
port name.
- No working link to the specified destination node can be found when sending
by port ID.
[ 本帖最后由 yjh777 于 2009-12-21 20:44 编辑 ] |
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