Issues with udp:send() and udp:sendto()

[ojmakke]

Hello, I am new to Lua here.

I have a receiver side code:

local socket = require("socket")
local ip, port = "127.0.0.1", 9999
local udp = assert(socket.udp())
udp:setsockname(ip, port)

while 1 do
    a  = assert(udp:receive());
    print(a);
end

And a transmitter code:

local socket = require("socket")
local ip, port = "127.0.0.1", 9999


local udp = assert(socket.udp())
udp:setpeername(ip, port)

a = ""
for ii = 1,10000 do
    a = a .. " " .. ii
end

--udp:sendto(a, ip, port)
udp:send(a)
udp:close()

Using this code, I can only send 8193 bytes. First question is: Why?

Now, if I remove udp:setpeername(ip, port)

and use: udp:sendto(a, ip, port)

I do not receive anything! Second question: Why?