Broadcast

FIFO Broadcast

1. two msgs $m_1$ and $m_2$ are broadcast by the same process, e.g all broadcasted by events on $p_1$, and $m_1$ is broadcast before $m_2$, then $m_1$ is delivered before $m_2$ on any processes
2. Msgs sent by different processes can be delivered in any order

Causal Broadcast

1. if $m_1$ broadcast before $m_2$, then $m_1$ is delivered before $m_2$ on all processes
2. concurrent msg can be delivered in any order.
3. causal broadcast implies FIFO broadcast

Total Order Broadcast

1. all msg are delivered in the same order on all processes
2. e.g, total 3 process, order of $p_1$ message delivered is blue, red, yellow, order of $p_2$ message delivered is also blue, red, yellow, likewise $p_3$

FIFO Total order Broadcast

Combination of FIFO broadcast and total order broadcast