diff --git a/src/livekit/openIDSFU.ts b/src/livekit/openIDSFU.ts
index 3ae003fb..f07bb035 100644
--- a/src/livekit/openIDSFU.ts
+++ b/src/livekit/openIDSFU.ts
@@ -7,9 +7,11 @@ Please see LICENSE in the repository root for full details.
 
 import { type IOpenIDToken, type MatrixClient } from "matrix-js-sdk";
 import { logger } from "matrix-js-sdk/lib/logger";
+import { type CallMembershipIdentityParts } from "matrix-js-sdk/lib/matrixrtc/EncryptionManager";
 
 import { FailToGetOpenIdToken } from "../utils/errors";
 import { doNetworkOperationWithRetry } from "../utils/matrix";
+import { Config } from "../config/Config";
 
 export interface SFUConfig {
   url: string;
@@ -33,8 +35,12 @@ export type OpenIDClientParts = Pick<
  */
 export async function getSFUConfigWithOpenID(
   client: OpenIDClientParts,
+  membership: CallMembershipIdentityParts,
   serviceUrl: string,
-  matrixRoomId: string,
+  livekitRoomAlias: string,
+  matrix2jwt: boolean,
+  delayEndpointBaseUrl?: string,
+  delayId?: string,
 ): Promise<SFUConfig> {
   let openIdToken: IOpenIDToken;
   try {
@@ -49,21 +55,31 @@ export async function getSFUConfigWithOpenID(
   logger.debug("Got openID token", openIdToken);
 
   logger.info(`Trying to get JWT for focus ${serviceUrl}...`);
-  const sfuConfig = await getLiveKitJWT(
-    client,
+  const args: [CallMembershipIdentityParts, string, string, IOpenIDToken] = [
+    membership,
     serviceUrl,
-    matrixRoomId,
+    livekitRoomAlias,
     openIdToken,
-  );
-  logger.info(`Got JWT from call's active focus URL.`);
-
-  return sfuConfig;
+  ];
+  if (matrix2jwt) {
+    const sfuConfig = await getLiveKitJWTWithDelayDelegation(
+      ...args,
+      delayEndpointBaseUrl,
+      delayId,
+    );
+    logger.info(`Got JWT from call's active focus URL.`);
+    return sfuConfig;
+  } else {
+    const sfuConfig = await getLiveKitJWT(...args);
+    logger.info(`Got JWT from call's active focus URL.`);
+    return sfuConfig;
+  }
 }
 
 async function getLiveKitJWT(
-  client: OpenIDClientParts,
+  membership: CallMembershipIdentityParts,
   livekitServiceURL: string,
-  roomName: string,
+  livekitRoomAlias: string,
   openIDToken: IOpenIDToken,
 ): Promise<SFUConfig> {
   try {
@@ -73,9 +89,9 @@ async function getLiveKitJWT(
         "Content-Type": "application/json",
       },
       body: JSON.stringify({
-        room: roomName,
+        room: livekitRoomAlias,
         openid_token: openIDToken,
-        device_id: client.getDeviceId(),
+        device_id: membership.deviceId,
       }),
     });
     if (!res.ok) {
@@ -86,3 +102,53 @@ async function getLiveKitJWT(
     throw new Error("SFU Config fetch failed with exception " + e);
   }
 }
+
+export async function getLiveKitJWTWithDelayDelegation(
+  membership: CallMembershipIdentityParts,
+  livekitServiceURL: string,
+  livekitRoomAlias: string,
+  openIDToken: IOpenIDToken,
+  delayEndpointBaseUrl?: string,
+  delayId?: string,
+): Promise<SFUConfig> {
+  const { userId, deviceId, memberId } = membership;
+
+  const body = {
+    room_id: livekitRoomAlias,
+    slot_id: "m.call#ROOM",
+    openid_token: openIDToken,
+    member: {
+      id: memberId,
+      claimed_user_id: userId,
+      claimed_device_id: deviceId,
+    },
+  };
+
+  let bodyDalayParts = {};
+  // Also check for empty string
+  if (delayId && delayEndpointBaseUrl) {
+    const delayTimeoutMs =
+      Config.get().matrix_rtc_session?.delayed_leave_event_delay_ms ?? 1000;
+    bodyDalayParts = {
+      delay_id: delayId,
+      delay_timeout: delayTimeoutMs,
+      delay_cs_api_url: delayEndpointBaseUrl,
+    };
+  }
+
+  try {
+    const res = await fetch(livekitServiceURL + "/get_token", {
+      method: "POST",
+      headers: {
+        "Content-Type": "application/json",
+      },
+      body: JSON.stringify({ ...body, ...bodyDalayParts }),
+    });
+    if (!res.ok) {
+      throw new Error("SFU Config fetch failed with status code " + res.status);
+    }
+    return await res.json();
+  } catch (e) {
+    throw new Error("SFU Config fetch failed with exception " + e);
+  }
+}
diff --git a/src/state/CallViewModel/CallViewModel.ts b/src/state/CallViewModel/CallViewModel.ts
index e1869cf6..23c58268 100644
--- a/src/state/CallViewModel/CallViewModel.ts
+++ b/src/state/CallViewModel/CallViewModel.ts
@@ -41,10 +41,12 @@ import {
 } from "rxjs";
 import { logger as rootLogger } from "matrix-js-sdk/lib/logger";
 import {
+  MembershipManagerEvent,
   type LivekitTransport,
   type MatrixRTCSession,
 } from "matrix-js-sdk/lib/matrixrtc";
 import { type IWidgetApiRequest } from "matrix-widget-api";
+import { type CallMembershipIdentityParts } from "matrix-js-sdk/lib/matrixrtc/EncryptionManager";
 
 import {
   LocalUserMediaViewModel,
@@ -98,7 +100,7 @@ import {
   type SpotlightLandscapeLayoutMedia,
   type SpotlightPortraitLayoutMedia,
 } from "../layout-types.ts";
-import { ElementCallError } from "../../utils/errors.ts";
+import { ElementCallError, UnknownCallError } from "../../utils/errors.ts";
 import { type ObservableScope } from "../ObservableScope.ts";
 import { createHomeserverConnected$ } from "./localMember/HomeserverConnected.ts";
 import {
@@ -375,8 +377,11 @@ export function createCallViewModel$(
   trackProcessorState$: Behavior<ProcessorState>,
 ): CallViewModel {
   const client = matrixRoom.client;
-  const userId = client.getUserId()!;
-  const deviceId = client.getDeviceId()!;
+  const userId = client.getUserId();
+  const deviceId = client.getDeviceId();
+  if (!(userId && deviceId))
+    throw new UnknownCallError(new Error("userId and deviceId are required"));
+
   const livekitKeyProvider = getE2eeKeyProvider(
     options.encryptionSystem,
     matrixRTCSession,
@@ -407,10 +412,29 @@ export function createCallViewModel$(
     memberships$,
   );
 
+  const ownMembershipIdentity: CallMembershipIdentityParts = {
+    userId,
+    deviceId,
+    memberId: `${userId}:${deviceId}`,
+  };
+
   const localTransport$ = createLocalTransport$({
     scope: scope,
     memberships$: memberships$,
+    ownMembershipIdentity,
     client,
+    useMatrix2$: scope.behavior(
+      options.matrixRTCMode$.pipe(map((v) => v === MatrixRTCMode.Matrix_2_0)),
+    ),
+    delayId$: scope.behavior(
+      (
+        fromEvent(
+          matrixRTCSession,
+          MembershipManagerEvent.DelayIdChanged,
+        ) as Observable<string | undefined>
+      ).pipe(map((v) => v ?? null)),
+      matrixRTCSession.delayId ?? null,
+    ),
     roomId: matrixRoom.roomId,
     useOldestMember$: scope.behavior(
       options.matrixRTCMode$.pipe(map((v) => v === MatrixRTCMode.Legacy)),
@@ -455,6 +479,7 @@ export function createCallViewModel$(
       ),
     ),
     logger: logger,
+    ownMembershipIdentity,
   });
 
   const matrixLivekitMembers$ = createMatrixLivekitMembers$({
@@ -485,6 +510,7 @@ export function createCallViewModel$(
     joinMatrixRTC: (transport: LivekitTransport) => {
       return enterRTCSession(
         matrixRTCSession,
+        ownMembershipIdentity,
         transport,
         connectOptions$.value,
       );
diff --git a/src/state/CallViewModel/localMember/LocalMember.test.ts b/src/state/CallViewModel/localMember/LocalMember.test.ts
index 6a9f196e..8de14039 100644
--- a/src/state/CallViewModel/localMember/LocalMember.test.ts
+++ b/src/state/CallViewModel/localMember/LocalMember.test.ts
@@ -24,6 +24,7 @@ import {
   mockLivekitRoom,
   mockMuteStates,
   withTestScheduler,
+  ownMemberMock,
 } from "../../../utils/test";
 import {
   TransportState,
@@ -108,6 +109,7 @@ describe("LocalMembership", () => {
 
       enterRTCSession(
         mockedSession,
+        ownMemberMock,
         {
           livekit_alias: "roomId",
           livekit_service_url: "http://my-well-known-service-url.com",
@@ -166,6 +168,7 @@ describe("LocalMembership", () => {
 
       enterRTCSession(
         mockedSession,
+        ownMemberMock,
         {
           livekit_alias: "roomId",
           livekit_service_url: "http://my-well-known-service-url.com",
diff --git a/src/state/CallViewModel/localMember/LocalMember.ts b/src/state/CallViewModel/localMember/LocalMember.ts
index 40fb62d6..6f554423 100644
--- a/src/state/CallViewModel/localMember/LocalMember.ts
+++ b/src/state/CallViewModel/localMember/LocalMember.ts
@@ -34,6 +34,7 @@ import {
 } from "rxjs";
 import { type Logger } from "matrix-js-sdk/lib/logger";
 import { deepCompare } from "matrix-js-sdk/lib/utils";
+import { type CallMembershipIdentityParts } from "matrix-js-sdk/lib/matrixrtc/EncryptionManager";
 
 import { constant, type Behavior } from "../../Behavior.ts";
 import { type IConnectionManager } from "../remoteMembers/ConnectionManager.ts";
@@ -657,6 +658,7 @@ interface EnterRTCSessionOptions {
 // Exported for unit testing
 export function enterRTCSession(
   rtcSession: MatrixRTCSession,
+  ownMembershipIdentity: CallMembershipIdentityParts,
   transport: LivekitTransport,
   { encryptMedia, matrixRTCMode }: EnterRTCSessionOptions,
 ): void {
@@ -674,7 +676,8 @@ export function enterRTCSession(
   const multiSFU = matrixRTCMode !== MatrixRTCMode.Legacy;
   // Multi-sfu does not need a preferred foci list. just the focus that is actually used.
   // TODO where/how do we track errors originating from the ongoing rtcSession?
-  rtcSession.joinRoomSession(
+  rtcSession.joinRTCSession(
+    ownMembershipIdentity,
     multiSFU ? [] : [transport],
     multiSFU ? transport : undefined,
     {
diff --git a/src/state/CallViewModel/localMember/LocalTransport.test.ts b/src/state/CallViewModel/localMember/LocalTransport.test.ts
index c1c36fa5..ba030757 100644
--- a/src/state/CallViewModel/localMember/LocalTransport.test.ts
+++ b/src/state/CallViewModel/localMember/LocalTransport.test.ts
@@ -9,7 +9,7 @@ import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 import { type CallMembership } from "matrix-js-sdk/lib/matrixrtc";
 import { BehaviorSubject } from "rxjs";
 
-import { mockConfig, flushPromises } from "../../../utils/test";
+import { mockConfig, flushPromises, ownMemberMock } from "../../../utils/test";
 import { createLocalTransport$ } from "./LocalTransport";
 import { constant } from "../../Behavior";
 import { Epoch, ObservableScope } from "../../ObservableScope";
@@ -32,10 +32,14 @@ describe("LocalTransport", () => {
       memberships$: constant(new Epoch<CallMembership[]>([])),
       client: {
         getDomain: () => "",
+        baseUrl: "example.org",
         // These won't be called in this error path but satisfy the type
         getOpenIdToken: vi.fn(),
         getDeviceId: vi.fn(),
       },
+      ownMembershipIdentity: ownMemberMock,
+      useMatrix2$: constant(false),
+      delayId$: constant("delay_id_mock"),
     });
     await flushPromises();
 
@@ -65,11 +69,15 @@ describe("LocalTransport", () => {
       useOldestMember$: constant(false),
       memberships$: constant(new Epoch<CallMembership[]>([])),
       client: {
+        baseUrl: "https://lk.example.org",
         // Use empty domain to skip .well-known and use config directly
         getDomain: () => "",
         getOpenIdToken: vi.fn(),
         getDeviceId: vi.fn(),
       },
+      ownMembershipIdentity: ownMemberMock,
+      useMatrix2$: constant(false),
+      delayId$: constant("delay_id_mock"),
     });
     localTransport$.subscribe(
       (o) => observations.push(o),
@@ -105,7 +113,11 @@ describe("LocalTransport", () => {
         getDomain: () => "",
         getOpenIdToken: vi.fn(),
         getDeviceId: vi.fn(),
+        baseUrl: "https://lk.example.org",
       },
+      ownMembershipIdentity: ownMemberMock,
+      useMatrix2$: constant(false),
+      delayId$: constant("delay_id_mock"),
     });
 
     openIdResolver.resolve?.({ url: "https://lk.example.org", jwt: "jwt" });
@@ -140,7 +152,11 @@ describe("LocalTransport", () => {
         getDomain: () => "",
         getOpenIdToken: vi.fn(),
         getDeviceId: vi.fn(),
+        baseUrl: "https://lk.example.org",
       },
+      ownMembershipIdentity: ownMemberMock,
+      useMatrix2$: constant(false),
+      delayId$: constant("delay_id_mock"),
     });
 
     openIdResolver.resolve?.({ url: "https://lk.example.org", jwt: "jwt" });
diff --git a/src/state/CallViewModel/localMember/LocalTransport.ts b/src/state/CallViewModel/localMember/LocalTransport.ts
index 1320b8c4..6c3e1cd0 100644
--- a/src/state/CallViewModel/localMember/LocalTransport.ts
+++ b/src/state/CallViewModel/localMember/LocalTransport.ts
@@ -23,6 +23,7 @@ import {
 } from "rxjs";
 import { logger as rootLogger } from "matrix-js-sdk/lib/logger";
 import { AutoDiscovery } from "matrix-js-sdk/lib/autodiscovery";
+import { type CallMembershipIdentityParts } from "matrix-js-sdk/lib/matrixrtc/EncryptionManager";
 
 import { type Behavior } from "../../Behavior.ts";
 import { type Epoch, type ObservableScope } from "../../ObservableScope.ts";
@@ -34,6 +35,7 @@ import {
 } from "../../../livekit/openIDSFU.ts";
 import { areLivekitTransportsEqual } from "../remoteMembers/MatrixLivekitMembers.ts";
 import { customLivekitUrl } from "../../../settings/settings.ts";
+import { type LivekitTransportWithVersion } from "../remoteMembers/ConnectionManager.ts";
 
 const logger = rootLogger.getChild("[LocalTransport]");
 
@@ -44,10 +46,13 @@ const logger = rootLogger.getChild("[LocalTransport]");
  */
 interface Props {
   scope: ObservableScope;
+  ownMembershipIdentity: CallMembershipIdentityParts;
   memberships$: Behavior<Epoch<CallMembership[]>>;
-  client: Pick<MatrixClient, "getDomain"> & OpenIDClientParts;
+  client: Pick<MatrixClient, "getDomain" | "baseUrl"> & OpenIDClientParts;
   roomId: string;
   useOldestMember$: Behavior<boolean>;
+  useMatrix2$: Behavior<boolean>;
+  delayId$: Behavior<string | null>;
 }
 
 /**
@@ -62,20 +67,26 @@ interface Props {
 export const createLocalTransport$ = ({
   scope,
   memberships$,
+  ownMembershipIdentity,
   client,
   roomId,
   useOldestMember$,
-}: Props): Behavior<LivekitTransport | null> => {
+  useMatrix2$,
+  delayId$,
+}: Props): Behavior<LivekitTransportWithVersion | null> => {
   /**
    * The transport over which we should be actively publishing our media.
    * undefined when not joined.
    */
   const oldestMemberTransport$ = scope.behavior(
     memberships$.pipe(
-      map(
-        (memberships) =>
-          memberships.value[0]?.getTransport(memberships.value[0]) ?? null,
-      ),
+      map((memberships) => {
+        const oldestMember = memberships.value[0];
+        const t = oldestMember?.getTransport(memberships.value[0]);
+        if (!t) return null;
+        // Here we will use the matrix2 information from the oldest member transport.
+        return { ...t, useMatrix2: oldestMember.kind === "rtc" };
+      }),
       first((t) => t != null && isLivekitTransport(t)),
     ),
     null,
@@ -87,12 +98,24 @@ export const createLocalTransport$ = ({
    *
    * @throws MatrixRTCTransportMissingError | FailToGetOpenIdToken
    */
-  const preferredTransport$: Behavior<LivekitTransport | null> = scope.behavior(
-    customLivekitUrl.value$.pipe(
-      switchMap((customUrl) => from(makeTransport(client, roomId, customUrl))),
-    ),
-    null,
-  );
+  const preferredTransport$: Behavior<LivekitTransportWithVersion | null> =
+    scope.behavior(
+      combineLatest([customLivekitUrl.value$, useMatrix2$, delayId$]).pipe(
+        switchMap(([customUrl, useMatrix2, delayId]) =>
+          from(
+            makeTransport(
+              client,
+              ownMembershipIdentity,
+              roomId,
+              customUrl,
+              useMatrix2,
+              delayId ?? undefined,
+            ),
+          ),
+        ),
+      ),
+      null,
+    );
 
   /**
    * The chosen transport we should advertise in our MatrixRTC membership.
@@ -123,10 +146,13 @@ const FOCI_WK_KEY = "org.matrix.msc4143.rtc_foci";
  * @throws MatrixRTCTransportMissingError | FailToGetOpenIdToken
  */
 async function makeTransport(
-  client: Pick<MatrixClient, "getDomain"> & OpenIDClientParts,
+  client: Pick<MatrixClient, "getDomain" | "baseUrl"> & OpenIDClientParts,
+  membership: CallMembershipIdentityParts,
   roomId: string,
   urlFromDevSettings: string | null,
-): Promise<LivekitTransport> {
+  matrix2jwt = false,
+  delayId?: string,
+): Promise<LivekitTransportWithVersion> {
   let transport: LivekitTransport | undefined;
   logger.trace("Searching for a preferred transport");
   //TODO refactor this to use the jwt service returned alias.
@@ -176,13 +202,18 @@ async function makeTransport(
     transport = transportFromConf;
   }
 
-  if (!transport) throw new MatrixRTCTransportMissingError(domain ?? ""); // this will call the jwt/sfu/get endpoint to pre create the livekit room.
+  if (!transport) throw new MatrixRTCTransportMissingError(domain ?? "");
 
+  // this will call the jwt/sfu/get endpoint to pre create the livekit room.
   await getSFUConfigWithOpenID(
     client,
+    membership,
     transport.livekit_service_url,
     transport.livekit_alias,
+    matrix2jwt,
+    client.baseUrl,
+    delayId,
   );
 
-  return transport;
+  return { ...transport, useMatrix2: matrix2jwt };
 }
diff --git a/src/state/CallViewModel/remoteMembers/Connection.test.ts b/src/state/CallViewModel/remoteMembers/Connection.test.ts
index 30c934b9..533f451a 100644
--- a/src/state/CallViewModel/remoteMembers/Connection.test.ts
+++ b/src/state/CallViewModel/remoteMembers/Connection.test.ts
@@ -27,7 +27,6 @@ import EventEmitter from "events";
 import { type IOpenIDToken } from "matrix-js-sdk";
 import { logger } from "matrix-js-sdk/lib/logger";
 
-import type { LivekitTransport } from "matrix-js-sdk/lib/matrixrtc";
 import {
   Connection,
   ConnectionState,
@@ -39,7 +38,8 @@ import {
   ElementCallError,
   FailToGetOpenIdToken,
 } from "../../../utils/errors.ts";
-import { mockRemoteParticipant } from "../../../utils/test.ts";
+import { mockRemoteParticipant, ownMemberMock } from "../../../utils/test.ts";
+import { type LivekitTransportWithVersion } from "./ConnectionManager.ts";
 
 let testScope: ObservableScope;
 
@@ -50,10 +50,11 @@ let fakeLivekitRoom: MockedObject<LivekitRoom>;
 let localParticipantEventEmiter: EventEmitter;
 let fakeLocalParticipant: MockedObject<LocalParticipant>;
 
-const livekitFocus: LivekitTransport = {
+const livekitFocus: LivekitTransportWithVersion = {
   livekit_alias: "!roomID:example.org",
   livekit_service_url: "https://matrix-rtc.example.org/livekit/jwt",
   type: "livekit",
+  useMatrix2: false,
 };
 
 function setupTest(): void {
@@ -137,7 +138,7 @@ function setupRemoteConnection(): Connection {
     return Promise.resolve();
   });
 
-  return new Connection(opts, logger);
+  return new Connection(opts, logger, ownMemberMock);
 }
 
 afterEach(() => {
@@ -156,7 +157,7 @@ describe("Start connection states", () => {
       scope: testScope,
       livekitRoomFactory: () => fakeLivekitRoom,
     };
-    const connection = new Connection(opts, logger);
+    const connection = new Connection(opts, logger, ownMemberMock);
 
     expect(connection.state$.getValue()).toEqual("Initialized");
   });
@@ -172,7 +173,7 @@ describe("Start connection states", () => {
       livekitRoomFactory: () => fakeLivekitRoom,
     };
 
-    const connection = new Connection(opts, logger);
+    const connection = new Connection(opts, logger, ownMemberMock);
 
     const capturedStates: (ConnectionState | Error)[] = [];
     const s = connection.state$.subscribe((value) => {
@@ -222,7 +223,7 @@ describe("Start connection states", () => {
       livekitRoomFactory: () => fakeLivekitRoom,
     };
 
-    const connection = new Connection(opts, logger);
+    const connection = new Connection(opts, logger, ownMemberMock);
 
     const capturedStates: (ConnectionState | Error)[] = [];
     const s = connection.state$.subscribe((value) => {
@@ -279,7 +280,7 @@ describe("Start connection states", () => {
       livekitRoomFactory: () => fakeLivekitRoom,
     };
 
-    const connection = new Connection(opts, logger);
+    const connection = new Connection(opts, logger, ownMemberMock);
 
     const capturedStates: (ConnectionState | Error)[] = [];
     const s = connection.state$.subscribe((value) => {
diff --git a/src/state/CallViewModel/remoteMembers/Connection.ts b/src/state/CallViewModel/remoteMembers/Connection.ts
index 05d0ec9e..d32bbce6 100644
--- a/src/state/CallViewModel/remoteMembers/Connection.ts
+++ b/src/state/CallViewModel/remoteMembers/Connection.ts
@@ -18,6 +18,7 @@ import {
 import { type LivekitTransport } from "matrix-js-sdk/lib/matrixrtc";
 import { BehaviorSubject, map } from "rxjs";
 import { type Logger } from "matrix-js-sdk/lib/logger";
+import { type CallMembershipIdentityParts } from "matrix-js-sdk/lib/matrixrtc/EncryptionManager";
 
 import {
   getSFUConfigWithOpenID,
@@ -35,7 +36,7 @@ import {
 
 export interface ConnectionOpts {
   /** The media transport to connect to. */
-  transport: LivekitTransport;
+  transport: LivekitTransport & { useMatrix2: boolean };
   /** The Matrix client to use for OpenID and SFU config requests. */
   client: OpenIDClientParts;
   /** The observable scope to use for this connection. */
@@ -88,7 +89,7 @@ export class Connection {
   /**
    * The media transport to connect to.
    */
-  public readonly transport: LivekitTransport;
+  public readonly transport: LivekitTransport & { useMatrix2: boolean };
 
   public readonly livekitRoom: LivekitRoom;
 
@@ -189,9 +190,18 @@ export class Connection {
   protected async getSFUConfigWithOpenID(): Promise<SFUConfig> {
     return await getSFUConfigWithOpenID(
       this.client,
+      this.ownMembershipIdentity,
       this.transport.livekit_service_url,
       this.transport.livekit_alias,
+      this.transport.useMatrix2,
     );
+    // client: OpenIDClientParts,
+    // membership: CallMembershipIdentityParts,
+    // serviceUrl: string,
+    // livekitRoomAlias: string,
+    // matrix2jwt: boolean,
+    // delayEndpointBaseUrl?: string,
+    // delayId?: string,
   }
 
   /**
@@ -220,7 +230,11 @@ export class Connection {
    *
    * @param logger
    */
-  public constructor(opts: ConnectionOpts, logger: Logger) {
+  public constructor(
+    opts: ConnectionOpts,
+    logger: Logger,
+    private ownMembershipIdentity: CallMembershipIdentityParts,
+  ) {
     this.logger = logger.getChild("[Connection]");
     this.logger.info(
       `[Connection] Creating new connection to ${opts.transport.livekit_service_url} ${opts.transport.livekit_alias}`,
diff --git a/src/state/CallViewModel/remoteMembers/ConnectionFactory.ts b/src/state/CallViewModel/remoteMembers/ConnectionFactory.ts
index 7c3a9eab..82a1a78a 100644
--- a/src/state/CallViewModel/remoteMembers/ConnectionFactory.ts
+++ b/src/state/CallViewModel/remoteMembers/ConnectionFactory.ts
@@ -5,7 +5,6 @@ SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
 Please see LICENSE in the repository root for full details.
 */
 
-import { type LivekitTransport } from "matrix-js-sdk/lib/matrixrtc";
 import {
   Room as LivekitRoom,
   type RoomOptions,
@@ -15,6 +14,7 @@ import {
 } from "livekit-client";
 import { type Logger } from "matrix-js-sdk/lib/logger";
 import E2EEWorker from "livekit-client/e2ee-worker?worker";
+import { type CallMembershipIdentityParts } from "matrix-js-sdk/lib/matrixrtc/EncryptionManager";
 
 import { type ObservableScope } from "../../ObservableScope.ts";
 import { Connection } from "./Connection.ts";
@@ -23,13 +23,15 @@ import type { MediaDevices } from "../../MediaDevices.ts";
 import type { Behavior } from "../../Behavior.ts";
 import type { ProcessorState } from "../../../livekit/TrackProcessorContext.tsx";
 import { defaultLiveKitOptions } from "../../../livekit/options.ts";
+import { type LivekitTransportWithVersion } from "./ConnectionManager.ts";
 
 // TODO evaluate if this should be done like the Publisher Factory
 export interface ConnectionFactory {
   createConnection(
-    transport: LivekitTransport,
+    transport: LivekitTransportWithVersion,
     scope: ObservableScope,
     logger: Logger,
+    ownMembershipIdentity: CallMembershipIdentityParts,
   ): Connection;
 }
 
@@ -77,10 +79,19 @@ export class ECConnectionFactory implements ConnectionFactory {
     this.livekitRoomFactory = livekitRoomFactory ?? defaultFactory;
   }
 
+  /**
+   *
+   * @param transport
+   * @param scope
+   * @param logger
+   * @param ownMembershipIdentity required to connect (using the jwt service) with the SFU.
+   * @returns
+   */
   public createConnection(
-    transport: LivekitTransport,
+    transport: LivekitTransportWithVersion,
     scope: ObservableScope,
     logger: Logger,
+    ownMembershipIdentity: CallMembershipIdentityParts,
   ): Connection {
     return new Connection(
       {
@@ -90,6 +101,7 @@ export class ECConnectionFactory implements ConnectionFactory {
         livekitRoomFactory: this.livekitRoomFactory,
       },
       logger,
+      ownMembershipIdentity,
     );
   }
 }
diff --git a/src/state/CallViewModel/remoteMembers/ConnectionManager.test.ts b/src/state/CallViewModel/remoteMembers/ConnectionManager.test.ts
index 70bfb4de..4ab91646 100644
--- a/src/state/CallViewModel/remoteMembers/ConnectionManager.test.ts
+++ b/src/state/CallViewModel/remoteMembers/ConnectionManager.test.ts
@@ -14,26 +14,29 @@ import { logger } from "matrix-js-sdk/lib/logger";
 import { Epoch, mapEpoch, ObservableScope } from "../../ObservableScope.ts";
 import {
   createConnectionManager$,
+  type LivekitTransportWithVersion,
   type ConnectionManagerData,
 } from "./ConnectionManager.ts";
 import { type ConnectionFactory } from "./ConnectionFactory.ts";
 import { type Connection } from "./Connection.ts";
-import { withTestScheduler } from "../../../utils/test.ts";
+import { ownMemberMock, withTestScheduler } from "../../../utils/test.ts";
 import { areLivekitTransportsEqual } from "./MatrixLivekitMembers.ts";
 import { type Behavior } from "../../Behavior.ts";
 
 // Some test constants
 
-const TRANSPORT_1: LivekitTransport = {
+const TRANSPORT_1: LivekitTransportWithVersion = {
   type: "livekit",
   livekit_service_url: "https://lk.example.org",
   livekit_alias: "!alias:example.org",
+  useMatrix2: false,
 };
 
-const TRANSPORT_2: LivekitTransport = {
+const TRANSPORT_2: LivekitTransportWithVersion = {
   type: "livekit",
   livekit_service_url: "https://lk.sample.com",
   livekit_alias: "!alias:sample.com",
+  useMatrix2: false,
 };
 
 let fakeConnectionFactory: ConnectionFactory;
@@ -80,6 +83,7 @@ describe("connections$ stream", () => {
           a: new Epoch([TRANSPORT_1, TRANSPORT_2], 0),
         }),
         logger: logger,
+        ownMembershipIdentity: ownMemberMock,
       });
 
       expectObservable(
@@ -124,6 +128,7 @@ describe("connections$ stream", () => {
           f: new Epoch([TRANSPORT_1, TRANSPORT_2], 5),
         }),
         logger: logger,
+        ownMembershipIdentity: ownMemberMock,
       });
 
       expectObservable(
@@ -166,6 +171,7 @@ describe("connections$ stream", () => {
           c: new Epoch([TRANSPORT_1], 2),
         }),
         logger: logger,
+        ownMembershipIdentity: ownMemberMock,
       });
 
       expectObservable(
@@ -279,6 +285,7 @@ describe("connectionManagerData$ stream", () => {
           a: new Epoch([TRANSPORT_1, TRANSPORT_2], 0),
         }),
         logger,
+        ownMembershipIdentity: ownMemberMock,
       });
 
       expectObservable(connectionManagerData$).toBe("abcd", {
diff --git a/src/state/CallViewModel/remoteMembers/ConnectionManager.ts b/src/state/CallViewModel/remoteMembers/ConnectionManager.ts
index 4303d50a..d5852d84 100644
--- a/src/state/CallViewModel/remoteMembers/ConnectionManager.ts
+++ b/src/state/CallViewModel/remoteMembers/ConnectionManager.ts
@@ -10,6 +10,7 @@ import { type LivekitTransport } from "matrix-js-sdk/lib/matrixrtc";
 import { combineLatest, map, of, switchMap, tap } from "rxjs";
 import { type Logger } from "matrix-js-sdk/lib/logger";
 import { type RemoteParticipant } from "livekit-client";
+import { type CallMembershipIdentityParts } from "matrix-js-sdk/lib/matrixrtc/EncryptionManager";
 
 import { type Behavior } from "../../Behavior.ts";
 import { type Connection } from "./Connection.ts";
@@ -18,6 +19,10 @@ import { generateItemsWithEpoch } from "../../../utils/observable.ts";
 import { areLivekitTransportsEqual } from "./MatrixLivekitMembers.ts";
 import { type ConnectionFactory } from "./ConnectionFactory.ts";
 
+export type LivekitTransportWithVersion = LivekitTransport & {
+  useMatrix2: boolean;
+};
+
 export class ConnectionManagerData {
   private readonly store: Map<string, [Connection, RemoteParticipant[]]> =
     new Map();
@@ -59,8 +64,9 @@ export class ConnectionManagerData {
 interface Props {
   scope: ObservableScope;
   connectionFactory: ConnectionFactory;
-  inputTransports$: Behavior<Epoch<LivekitTransport[]>>;
+  inputTransports$: Behavior<Epoch<LivekitTransportWithVersion[]>>;
   logger: Logger;
+  ownMembershipIdentity: CallMembershipIdentityParts;
 }
 
 // TODO - write test for scopes (do we really need to bind scope)
@@ -87,6 +93,7 @@ export function createConnectionManager$({
   connectionFactory,
   inputTransports$,
   logger: parentLogger,
+  ownMembershipIdentity,
 }: Props): IConnectionManager {
   const logger = parentLogger.getChild("[ConnectionManager]");
   // TODO logger: only construct one logger from the client and make it compatible via a EC specific sing
@@ -119,20 +126,26 @@ export function createConnectionManager$({
         function* (transports) {
           for (const transport of transports)
             yield {
-              keys: [transport.livekit_service_url, transport.livekit_alias],
+              keys: [
+                transport.livekit_service_url,
+                transport.livekit_alias,
+                transport.useMatrix2,
+              ],
               data: undefined,
             };
         },
-        (scope, _data$, serviceUrl, alias) => {
+        (scope, _data$, serviceUrl, alias, useMatrix2) => {
           logger.debug(`Creating connection to ${serviceUrl} (${alias})`);
           const connection = connectionFactory.createConnection(
             {
               type: "livekit",
               livekit_service_url: serviceUrl,
               livekit_alias: alias,
+              useMatrix2,
             },
             scope,
             logger,
+            ownMembershipIdentity,
           );
           // Start the connection immediately
           // Use connection state to track connection progress
@@ -187,12 +200,12 @@ export function createConnectionManager$({
   return { connectionManagerData$ };
 }
 
-function removeDuplicateTransports(
-  transports: LivekitTransport[],
-): LivekitTransport[] {
+function removeDuplicateTransports<T extends LivekitTransport>(
+  transports: T[],
+): T[] {
   return transports.reduce((acc, transport) => {
     if (!acc.some((t) => areLivekitTransportsEqual(t, transport)))
       acc.push(transport);
     return acc;
-  }, [] as LivekitTransport[]);
+  }, [] as T[]);
 }
diff --git a/src/state/CallViewModel/remoteMembers/ECConnectionFactory.test.ts b/src/state/CallViewModel/remoteMembers/ECConnectionFactory.test.ts
index 0c439a6b..3c60e776 100644
--- a/src/state/CallViewModel/remoteMembers/ECConnectionFactory.test.ts
+++ b/src/state/CallViewModel/remoteMembers/ECConnectionFactory.test.ts
@@ -15,7 +15,11 @@ import EventEmitter from "events";
 import { ObservableScope } from "../../ObservableScope.ts";
 import { ECConnectionFactory } from "./ConnectionFactory.ts";
 import type { OpenIDClientParts } from "../../../livekit/openIDSFU.ts";
-import { exampleTransport, mockMediaDevices } from "../../../utils/test.ts";
+import {
+  exampleTransport,
+  mockMediaDevices,
+  ownMemberMock,
+} from "../../../utils/test.ts";
 import type { ProcessorState } from "../../../livekit/TrackProcessorContext.tsx";
 import { constant } from "../../Behavior";
 
@@ -72,7 +76,12 @@ describe("ECConnectionFactory - Audio inputs options", () => {
         echo,
         noise,
       );
-      ecConnectionFactory.createConnection(exampleTransport, testScope, logger);
+      ecConnectionFactory.createConnection(
+        exampleTransport,
+        testScope,
+        logger,
+        ownMemberMock,
+      );
 
       // Check if Room was constructed with expected options
       expect(RoomConstructor).toHaveBeenCalledWith(
@@ -113,7 +122,12 @@ describe("ECConnectionFactory - ControlledAudioDevice", () => {
         false,
         false,
       );
-      ecConnectionFactory.createConnection(exampleTransport, testScope, logger);
+      ecConnectionFactory.createConnection(
+        exampleTransport,
+        testScope,
+        logger,
+        ownMemberMock,
+      );
 
       // Check if Room was constructed with expected options
       expect(RoomConstructor).toHaveBeenCalledWith(
diff --git a/src/state/CallViewModel/remoteMembers/MatrixLivekitMembers.ts b/src/state/CallViewModel/remoteMembers/MatrixLivekitMembers.ts
index 0c61ba06..9178c347 100644
--- a/src/state/CallViewModel/remoteMembers/MatrixLivekitMembers.ts
+++ b/src/state/CallViewModel/remoteMembers/MatrixLivekitMembers.ts
@@ -176,9 +176,9 @@ export function createMatrixLivekitMembers$({
 // TODO add back in the callviewmodel pauseWhen(this.pretendToBeDisconnected$)
 
 // TODO add this to the JS-SDK
-export function areLivekitTransportsEqual(
-  t1: LivekitTransport | null,
-  t2: LivekitTransport | null,
+export function areLivekitTransportsEqual<T extends LivekitTransport>(
+  t1: T | null,
+  t2: T | null,
 ): boolean {
   if (t1 && t2) return t1.livekit_service_url === t2.livekit_service_url;
   // In case we have different lk rooms in the same SFU (depends on the livekit authorization service)
diff --git a/src/state/CallViewModel/remoteMembers/integration.test.ts b/src/state/CallViewModel/remoteMembers/integration.test.ts
index 202b3f56..c9e02a7c 100644
--- a/src/state/CallViewModel/remoteMembers/integration.test.ts
+++ b/src/state/CallViewModel/remoteMembers/integration.test.ts
@@ -24,6 +24,7 @@ import {
   mockCallMembership,
   mockComputeLivekitParticipantIdentity$,
   mockMediaDevices,
+  ownMemberMock,
   withTestScheduler,
 } from "../../../utils/test.ts";
 import { type ProcessorState } from "../../../livekit/TrackProcessorContext.tsx";
@@ -128,6 +129,7 @@ test("bob, carl, then bob joining no tracks yet", () => {
       connectionFactory: ecConnectionFactory,
       inputTransports$: membershipsAndTransports.transports$,
       logger: logger,
+      ownMembershipIdentity: ownMemberMock,
     });
 
     const matrixLivekitItems$ = createMatrixLivekitMembers$({
diff --git a/src/state/SessionBehaviors.ts b/src/state/SessionBehaviors.ts
index e174a1cc..b61d2fe6 100644
--- a/src/state/SessionBehaviors.ts
+++ b/src/state/SessionBehaviors.ts
@@ -8,7 +8,6 @@ Please see LICENSE in the repository root for full details.
 import {
   type CallMembership,
   isLivekitTransport,
-  type LivekitTransport,
   type MatrixRTCSession,
   MatrixRTCSessionEvent,
 } from "matrix-js-sdk/lib/matrixrtc";
@@ -21,15 +20,18 @@ import {
   type ObservableScope,
 } from "./ObservableScope";
 import { type Behavior } from "./Behavior";
+import { type LivekitTransportWithVersion } from "./CallViewModel/remoteMembers/ConnectionManager";
 
 export const membershipsAndTransports$ = (
   scope: ObservableScope,
   memberships$: Behavior<Epoch<CallMembership[]>>,
 ): {
   membershipsWithTransport$: Behavior<
-    Epoch<{ membership: CallMembership; transport?: LivekitTransport }[]>
+    Epoch<
+      { membership: CallMembership; transport?: LivekitTransportWithVersion }[]
+    >
   >;
-  transports$: Behavior<Epoch<LivekitTransport[]>>;
+  transports$: Behavior<Epoch<LivekitTransportWithVersion[]>>;
 } => {
   /**
    * Lists the transports used by ourselves, plus all other MatrixRTC session
@@ -47,7 +49,12 @@ export const membershipsAndTransports$ = (
           const transport = membership.getTransport(oldestMembership);
           return {
             membership,
-            transport: isLivekitTransport(transport) ? transport : undefined,
+            transport: isLivekitTransport(transport)
+              ? {
+                  ...transport,
+                  useMatrix2: membership.kind === "rtc",
+                }
+              : undefined,
           };
         });
       }),
diff --git a/src/utils/test.ts b/src/utils/test.ts
index 7d251640..968b7160 100644
--- a/src/utils/test.ts
+++ b/src/utils/test.ts
@@ -25,7 +25,6 @@ import {
 import {
   CallMembership,
   type LivekitFocusSelection,
-  type LivekitTransport,
   type MatrixRTCSession,
   MatrixRTCSessionEvent,
   type MatrixRTCSessionEventHandlerMap,
@@ -67,6 +66,7 @@ import { type MediaDevices } from "../state/MediaDevices";
 import { type Behavior, constant } from "../state/Behavior";
 import { ObservableScope } from "../state/ObservableScope";
 import { MuteStates } from "../state/MuteStates";
+import { type LivekitTransportWithVersion } from "../state/CallViewModel/remoteMembers/ConnectionManager";
 
 export function withFakeTimers(continuation: () => void): void {
   vi.useFakeTimers();
@@ -197,10 +197,11 @@ export function mockEmitter<T>(): EmitterMock<T> {
   };
 }
 
-export const exampleTransport: LivekitTransport = {
+export const exampleTransport: LivekitTransportWithVersion = {
   type: "livekit",
   livekit_service_url: "https://lk.example.org",
   livekit_alias: "!alias:example.org",
+  useMatrix2: false,
 };
 
 export function mockCallMembership(
@@ -256,6 +257,11 @@ export function mockRtcMembership(
   return cms;
 }
 
+export const ownMemberMock: CallMembershipIdentityParts = {
+  userId: "@alice:example.org",
+  deviceId: "DEVICE",
+  memberId: "@alice:example.org:DEVICE",
+};
 // Maybe it'd be good to move this to matrix-js-sdk? Our testing needs are
 // rather simple, but if one util to mock a member is good enough for us, maybe
 // it's useful for matrix-js-sdk consumers in general.
diff --git a/yarn.lock b/yarn.lock
index db1db491..a3211330 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -10338,9 +10338,9 @@ __metadata:
   languageName: node
   linkType: hard
 
-"matrix-js-sdk@github:matrix-org/matrix-js-sdk#head=toger5/use-membershipID-for-session-state-events&commit=f5f1b8efb46b3d55a7eebfabb4a61496640b8b00":
-  version: 39.3.0
-  resolution: "matrix-js-sdk@https://github.com/matrix-org/matrix-js-sdk.git#commit=f5f1b8efb46b3d55a7eebfabb4a61496640b8b00"
+"matrix-js-sdk@portal:/Users/timo/Projects/matrix-js-sdk::locator=element-call%40workspace%3A.":
+  version: 0.0.0-use.local
+  resolution: "matrix-js-sdk@portal:/Users/timo/Projects/matrix-js-sdk::locator=element-call%40workspace%3A."
   dependencies:
     "@babel/runtime": "npm:^7.12.5"
     "@matrix-org/matrix-sdk-crypto-wasm": "npm:^16.0.0"
@@ -10356,9 +10356,8 @@ __metadata:
     sdp-transform: "npm:^3.0.0"
     unhomoglyph: "npm:^1.0.6"
     uuid: "npm:13"
-  checksum: 10c0/9607b0c063c873a24c1a2d05cc7500d60c32556ec82b666ebaae5c5e829faf5bb7639780efddea7211e6b9873098bd53b97656f041e932e8b0de0c208ccabbff
   languageName: node
-  linkType: hard
+  linkType: soft
 
 "matrix-widget-api@npm:^1.14.0":
   version: 1.15.0