I do not want to use GameKit. I am trying to use a low-level approach using dns_sd.h and methods like DNSServiceRegister to establish and maintain a connection. However, I found a wrapper for this called HHServices... Honestly at this point either a low-level answer using dns_sd or a high-level answer using HHServices is welcome.

Here is HHServices. Here is GCDAsyncSocket.

This is the code I have so far. I am able to successfully publish the HHService and the GCDAsyncSocket, and also start browing for HHServices on the other device, but no connection is made. Any help? :D

Server Side

Here's where I publish the HHService:

//....
NSUInteger serverPort = 19997;
HHServicePublisher *publisher = [[HHServicePublisher alloc] initWithName:@"MyDisplayName" type:@"_myexampleservice._tcp." domain:@"local." txtData:nil port:serverPort];

GCDAsyncSocket *listenSocket = [[GCDAsyncSocket alloc] initWithDelegate:self delegateQueue:dispatch_get_main_queue()];

NSError *error = nil;
if (![listenSocket acceptOnPort:serverPort error:&error])
{
    [self alert:@"Error starting GCDAsyncsocket"];
}


publisher.delegate = self;
if(![publisher beginPublish])
{
    [self alert:@"Error publishing HHService"];
}
else
{
    [self alert:@"Successfully published HHService"];
}

This is where I see if a client connected:

- (void)socket:(GCDAsyncSocket *)sender didAcceptNewSocket:(GCDAsyncSocket *)newSocket
{
    [self alert:@"didAcceptNewSocket!"];
}

---

Client-side

Where I start browsing

    HHServiceBrowser *browser = [[HHServiceBrowser alloc] initWithType:@"_myexampleservice._tcp." domain:@"local."];
    browser.delegate = self;
    if(![browser beginBrowse])
    {
        [self alert:@"Couldn't start browsing"];
    }
    else
    {
        [self alert:@"Successfully started browsing"];
    }

Callback for finding the published HHService:

- (void) serviceBrowser:(HHServiceBrowser*)serviceBrowser didFindService:(HHService*)service moreComing:(BOOL)moreComing {
    [self alert:@"Found a service! "];
}

Could someone shed some light as to what I'm doing wrong?

HHServices only handles discovery. It's up to you to make the connection. You need to resolve the service, then open a socket, like it shows in the HHServices example.