[quote='869237022, DTS Engineer, /thread/808917?answerId=869237022#869237022'] reproduce this here in my office [/quote] If possible could you use TLS 1.3 and a PKCS#12 identity?

[quote='869237022, DTS Engineer, /thread/808917?answerId=869237022#869237022'] Admittedly, that was all prior to iOS 26, so it’s possible we broke something. I’m gonna try to reproduce this here in my office, but I won’t have time to do that until after the winter break. [/quote] Thank you for taking the time to investigate this. I look forward to hearing back about what you find. Would me checking in on Jan 5th be appropriate?

[quote='869086022, DTS Engineer, /thread/808917?answerId=869086022#869086022'] Create a small test app [/quote] I created four branches on my app: ios18_network_api_tcp ios18_network_api_quic ios26_network_api_tcp ios26_network_api_quic I have three physical devices to test with: iPad (Device A - iOS 26 - no cellular) iPhone (Device B - iOS 26 - no cellular) iPhone (Device C - iOS 26 - yes cellular) For each branch listed above I tested two scenarios: home Wi-Fi network ON home Wi-Fi network OFF (I physically turned off the router) Note that on each device the Wi-Fi toggle is ON. Results from each branch for home Wi-Fi ON: Devices A, B and C can all discovery and connect to each other Results from each branch for home Wi-Fi OFF: Devices A and B can discovery and connect to each other Device C is not able to discovery or connect to the other devices

I’m not sure why you think cellular is a factor here. It is not. Peer-to-peer Wi-Fi is independent of cellular. I think this because things work (ie multiple devices are able to discover and connect to each other when no wifi network is available) only for devices without cellular. If i load the exact same app onto devices with cellular and try the same thing they are not able to discovery and connect to each other.

[quote='869086022, DTS Engineer, /thread/808917?answerId=869086022#869086022'] Create a small test app that uses [/quote] Are you open to me inviting you to a private Github repo?

The answer to this is no. Cursor said so and I tried everything I and Cursor could think of and nothing worked.

[quote='867322022, DTS Engineer, /thread/808198?answerId=867322022#867322022'] Can you share an example crash report? [/quote] my app was crashing because I was improperly saving the stream I would create like this try await connection.inboundStreams(prepending: { quicStream in TLV { quicStream } }) { stream in await self.receiveMessages(from: stream, connectionID: connectionID) } I learned via Cursor that those streams are one time use and do not need to be saved.

Hi Quinn @DTS Engineer I am curious if my post is missing any information needed to troubleshoot my issue. I searched through the forums and online and haven't found my specific issue anywhere. The more I think about it I come to the following: true peer to peer with no wifi network works with iOS devices without cellular (so AWDL is used) once cellular is introduced there needs to be a wifi network because using AWDL is not an option Maybe some kind of option can be passed into the NetworkListener or when creating a NetworkConnection that would prompt apple's code to try to use AWDL if the peer to peer option is true? [quote='867952022, DTS Engineer, /thread/808917?answerId=867952022#867952022'] Share and Enjoy [/quote]

Bumping to not lose visibility.

Hi @DTS Engineer - I wanted to check in and see if there is any things else I can shared that would help in troubleshooting my issue?

I also tried loading my app onto two physical iPhones (both running iOS 26) that have cellular and they were not able to discover each other. I also tried builder = builder.expensivePathsProhibited(true) and parameters.prohibitExpensivePaths = true but it did not help.

Bump to not lose visibility.

@DTS Engineer bumping to not lose eyes

@DTS Engineer - Here is how I build an outbound connection: private func handleOutboundConnection(to endpoint: NWEndpoint, deviceID: DeviceID) { do { guard let identity = Utils.importIdentityFromPKCS12() else { logger.error("[networkBrowser] could not import identity") return } guard let certificateData = Utils.getCertificateData(from: identity) else { logger.error("[networkBrowser] could not read certificate data") return } let builder = try makeQUICParametersBuilder(identity: identity, certificateData: certificateData) let connection = NetworkConnection(to: endpoint, using: builder) let connectionID = ConnectionID(connection) // connectionIDToConnection[connectionID] = connection // associateConnection(connectionID, with: deviceID) print("handleOutboundConnection: connection added") setupConnectionStateTask(for: connection, connectionID: connectionID, origin: .browser, deviceID: deviceID) setupConnectionReceiveTask(for: connection, connectionID: connectionID) } catch { print("could not create NetworkConnection: \(error)") } }

To add more info to this I tried the following. I have this going in my app: let m = NWPathMonitor() m.pathUpdateHandler = { [weak self] path in print("pathUpdateHandler: \(path)") print("path.debugDescription: \(path.debugDescription)") print("path.unsatisfiedReason: \(path.unsatisfiedReason)") print("path.status: \(path.status)") print("path.isExpensive: \(path.isExpensive)") print("path.isConstrained: \(path.isConstrained)") print("path.isUltraConstrained: \(path.isUltraConstrained)") print("path.availableInterfaces: \(path.availableInterfaces)") print("path.availableInterfaces.count: \(path.availableInterfaces.count)") path.availableInterfaces.forEach { print("interface: \($0)") } Task { await self?.broadcast(path) } } On the iPhone with NO cellular (device A) - while on the wifi network - I see [en0, en0] for availableInterfaces On the iPhone with cellular (device B) - while on the wifi network - I see [en0, en0, pdp_ip0, pdp_ip0] for availableInterfaces When i cut off the wifi network device A shows [] for availableInterfaces When i cut off the wifi network device B shows [pdp_ip0, pdp_ip0] for availableInterfaces When i then toggle on airplane mode on device B but toggle on wifi I see [] for availableInterfaces So at this point device A and device B are showing the same availableInterfaces - but they still can't connect. They can discovery each other but the connection never makes it to the TLS stage. Below are my logs from having no wifi network, device A has its Device Discovery running (ie NetworkBrowser up and running and NetworkListener up and running) - device A has its wifi toggle on device B has its Device Discovery running (ie NetworkBrowser up and running and NetworkListener up and running) - device B has its wifi toggle on [MessageService] new subscriber added local network service -> browser state update handler: ready unsubscribe voice control commands here in on termination of voice control local network service -> browser state update handler: cancelled [startBrowser]: browser is ready [L1 ready, local endpoint: <NULL>, parameters: quic, local: ::.0, definite, attribution: developer, server, port: 61566, path satisfied (Path is satisfied), viable, interface: pdp_ip0[lte], ipv4, ipv6, dns, expensive, uses cell, LQM: good, service: 8FB0D9E1-303A-47E2-B15A-6826279577D7._captadoh._udp.<NULL> txtLength:0]: ready Listener ready onServiceRegistrationUpdate: added 8FB0D9E1-303A-47E2-B15A-6826279577D7._captadoh._udp.local. [NetworkingService] handleBrowserEndpoints skipping self endpoint: 8FB0D9E1-303A-47E2-B15A-6826279577D7 handleOutboundConnection: connection added here in setupConnectionReceiveTask nw_resolver_start_query_timer_block_invoke [C2.1.1] Query fired: did not receive all answers in time for b4f40bc0-c586-4946-a2f3-950fb21fddeb.local.:64458 [NetworkingService] handleBrowserEndpoints skipping self endpoint: 8FB0D9E1-303A-47E2-B15A-6826279577D7 [NetworkingService] handleEndpointRemoved removed endpoint for 354C4D39-2CA4-4A06-9F41-8A9B755C025B nw_connection_copy_protocol_metadata_internal_block_invoke [C3] Client called nw_connection_copy_protocol_metadata_internal on unconnected nw_connection nw_connection_copy_protocol_metadata_internal_block_invoke [C3] Client called nw_connection_copy_protocol_metadata_internal on unconnected nw_connection nw_connection_copy_connected_local_endpoint_block_invoke [C3] Client called nw_connection_copy_connected_local_endpoint on unconnected nw_connection nw_connection_copy_connected_remote_endpoint_block_invoke [C3] Client called nw_connection_copy_connected_remote_endpoint on unconnected nw_connection nw_endpoint_flow_failed_with_error [C2.1.1.1 fe80::7cc9:daff:fea6:9151%awdl0.64458 in_progress channel-flow (satisfied (Path is satisfied), viable, interface: awdl0[802.11], scoped, uses wifi, LQM: good)] already failing, returning [NetworkingService] handleBrowserEndpoints skipping self endpoint: 8FB0D9E1-303A-47E2-B15A-6826279577D7 handleOutboundConnection: connection added here in setupConnectionReceiveTask nw_resolver_start_query_timer_block_invoke [C4.1.1] Query fired: did not receive all answers in time for b4f40bc0-c586-4946-a2f3-950fb21fddeb.local.:64458 [NetworkingService] handleBrowserEndpoints skipping self endpoint: 8FB0D9E1-303A-47E2-B15A-6826279577D7 [NetworkingService] handleEndpointRemoved removed endpoint for 354C4D39-2CA4-4A06-9F41-8A9B755C025B nw_connection_copy_protocol_metadata_internal_block_invoke [C5] Client called nw_connection_copy_protocol_metadata_internal on unconnected nw_connection nw_connection_copy_protocol_metadata_internal_block_invoke [C5] Client called nw_connection_copy_protocol_metadata_internal on unconnected nw_connection nw_connection_copy_connected_local_endpoint_block_invoke [C5] Client called nw_connection_copy_connected_local_endpoint on unconnected nw_connection nw_connection_copy_connected_remote_endpoint_block_invoke [C5] Client called nw_connection_copy_connected_remote_endpoint on unconnected nw_connection nw_endpoint_flow_failed_with_error [C4.1.1.1 fe80::7cc9:daff:fea6:9151%awdl0.64458 in_progress channel-flow (satisfied (Path is satisfied), viable, interface: awdl0[802.11], scoped, uses wifi, LQM: good)] already failing, returning Note that device A has the device ID 354C4D39-2CA4-4A06-9F41-8A9B755C025B - device B has the device ID 8FB0D9E1-303A-47E2-B15A-6826279577D7