Release 10.1A: OpenEdge Development:
Messaging and ESB

Comparing PTP and Pub/Sub messaging

There are several distinguishing characters between the two message models. Table 2–5 compares PTP and Pub/Sub messaging.

Table 2–5: Comparing features 

PTP	Pub/Sub
There is one consumer per message.	There are multiple consumers per message.
The receiver can browse the queue of undelivered messages.	Receivers only see delivered messages.
The Message broker balances the load of message delivery.	All subscribers receive messages (unless using shared subscription or message selectors).
The receiver controls the number of messages transferred from the broker.	The broker delivers one message at a time.
Message consumers can use message selectors to filter messages.	Message consumers can use message selectors to filter messages.
Support request/reply.	Support request/reply.
Queues permit Message Consumers to receive messages sent while disconnected.	Durable subscriptions permit Message Consumers to receive messages sent while disconnected.