# ZMQ - correct usage
**URL:** https://discourse.julialang.org/t/zmq-correct-usage/9734
**Category:** General Usage
**Created:** [March 15, 2018, 11:17am UTC](https://discourse.julialang.org/t/zmq-correct-usage/9734 "2018-03-15T11:17:44Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@msomers](https://discourse.julialang.org/u/msomers)
#### Post date: [March 15, 2018, 11:17am UTC](https://discourse.julialang.org/t/zmq-correct-usage/9734/1 "2018-03-15T11:17:44Z")
trying to get a simple ZMQ communication going connecting to a simple python echo server
```julia
import zmq
# ZeroMQ Context
context = zmq.Context()
# Define the socket using the "Context"
sock = context.socket(zmq.REP)
sock.bind("tcp://127.0.0.1:1234")
# Run a simple "Echo" server
while True:
message = sock.recv()
sock.send("Echo: " + message)
print "Echo: " + message
```
Julia code for the client looks like
```julia
using ZMQ
const ctx = Context()
const sock = Socket(ctx, REQ)
ZMQ.connect(sock, "tcp://127.0.0.1:1234")
ZMQ.send(sock, "SUCCESS")
```
that works for the first connection - but there doesn’t appear to be persistance if I send
ZMQ.send(sock, “SUCCESS”)
I have to reestablish context like
```julia
ctx = Context()
s = Socket(ctx, REQ)
ZMQ.connect(s, "tcp://localhost:1234")
```
and not
`ZMQ.send(sock, "SUCCESS")`
that cant be right is it
tks
---
### Author:  [@rdeits](https://discourse.julialang.org/u/rdeits)
#### Post date: [March 15, 2018, 2:35pm UTC](https://discourse.julialang.org/t/zmq-correct-usage/9734/2 "2018-03-15T14:35:51Z")
You need to call `recv(sock)` from Julia after every time you call `send`, otherwise you won’t be able to send any more messages. This is just part of the required behavior of a REQ-REP connection.