sverchok networking mk2 halv-proceed node. to get worked remove on startup old ones and insert first receiver and than sender node, activate them.

udp_client.py

# ##### BEGIN GPL LICENSE BLOCK #####
#
#  This program is free software; you can redistribute it and/or
#  modify it under the terms of the GNU General Public License
#  as published by the Free Software Foundation; either version 2
#  of the License, or (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
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#  along with this program; if not, write to the Free Software Foundation,
#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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# ##### END GPL LICENSE BLOCK #####

import socket
import threading, time, ast

import bpy
from bpy.props import IntProperty, FloatProperty, EnumProperty, StringProperty, BoolProperty
from sverchok.node_tree import SverchCustomTreeNode, StringsSocket
from sverchok.utils.profile import profile
from sverchok.data_structure import updateNode


class UdpClientNode(bpy.types.Node, SverchCustomTreeNode):

    bl_idname = 'UdpClientNode'
    bl_label = 'UDP Client'

    def send_msg(self, context):
        sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        sock.setblocking(0)
        sock.sendto(bytes(self.send, 'UTF-8'), (self.ip, self.port))


    def recv_msg(self,context):
        while True:
            try:
                sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
                sock.bind((self.ip, self.port))
                sock.settimeout(self.timeout)
                data = sock.recv(self.buffer_size)
                print(data)
                if data:
                    self.receive = data.decode('UTF-8')
            except socket.timeout:
                pass
                #print('Timeout')


    send = StringProperty(name='send',
                          description='Message to send',
                          default='message',
                          update=send_msg)

    receive = StringProperty(name='receive',
                             description='Received message',
                             default='',
                             update=updateNode)

    ip = StringProperty(name='ip',
                        description='IP address of server',
                        default='127.0.0.1')

    port = IntProperty(name='port',
                       description='Port number to send message',
                       default=9250)

    buffer_size = IntProperty(name='buffer_size',
                              description='Size of buffer',
                              default=8192)

    timeout = FloatProperty(name='timeout',
                            description='Timeout (sec)',
                            default=0.5)

    active = BoolProperty(default=False, name='Active')

    def draw_buttons(self, context, layout):
        layout.prop(self, 'active', text='Active')
        layout.prop(self, 'ip', text='IP')
        layout.prop(self, 'port', text='Port')
        layout.prop(self, 'buffer_size', text='Buffer')
        layout.prop(self, 'timeout', text='Timeout')

    def sv_init(self, context):
        self.inputs.new('StringsSocket', 'send') #.prop_name = 'send'
        self.outputs.new('StringsSocket', 'receive')
        ev = threading.Thread(target=self.recv_msg, args=(context,))
        ev.start()

    @profile
    def process(self):
        if not self.active:
            return
        if self.inputs[0].is_linked:
            input_value = self.inputs[0].sv_get()
            if self.send != str(input_value):
                
                self.send = str(input_value)
                self.send_msg(bpy.context)
                #print(type(self.send),type(self.ip),type(self.port))
                #print('sent message',(self.ip),(self.port))

        elif self.outputs['receive'].is_linked:
            #self.recv_msg()
            self.outputs['receive'].sv_set(ast.literal_eval(self.receive))


def register():
    bpy.utils.register_class(UdpClientNode)


def unregister():
    bpy.utils.unregister_class(UdpClientNode)

if __name__ == '__main__':
    register()