diff --git a/src/Center/Center.ts b/src/Center/Center.ts
index 40de5e5..4e8d868 100644
--- a/src/Center/Center.ts
+++ b/src/Center/Center.ts
@@ -5,19 +5,25 @@ import {JobEvents} from "../Job/JobEvents";
 import Logger from "../Logger";
 import {SmppSession} from "../SmppSession";
 import {CenterEvents} from "./CenterEvents";
+import {CenterPDUProcessor} from "./CenterPDUProcessor";
 import CenterStatus from "./CenterStatus";
 
 const NanoTimer = require('nanotimer');
 const smpp = require("smpp");
 
+const MESSAGE_SEND_UPDATE_DELAY: number = Number(process.env.MESSAGE_SEND_UPDATE_DELAY) || 500;
+
 export class Center implements SmppSession {
 	port: number;
 	private pendingSessions: any[] = [];
 	private sessions: any[] = [];
+	private nextSession: number = 0;
 	private server: any;
 	private eventEmitter: EventEmitter = new EventEmitter();
 	private readonly logger: Logger;
 	private readonly _id: number;
+	private sendTimer: any | null = null;
+	private counterUpdateTimer: any | null = null;
 
 	constructor(id: number, port: number, username: string, password: string) {
 		this._id = id;
@@ -30,8 +36,20 @@ export class Center implements SmppSession {
 		this.initialize();
 	}
 
+	// TODO: Implement a few modes and set this to default DEBUG
+	private _processor: CenterPDUProcessor | undefined;
+
+	set processor(value: CenterPDUProcessor) {
+		this._processor = value;
+		this.eventEmitter.emit(CenterEvents.STATE_CHANGED, this.serialize());
+	}
+
 	private _defaultMultipleJob!: Job;
 
+	get defaultMultipleJob(): Job {
+		return this._defaultMultipleJob;
+	}
+
 	set defaultMultipleJob(value: Job) {
 		this._defaultMultipleJob = value;
 		this.eventEmitter.emit(CenterEvents.STATE_CHANGED, this.serialize());
@@ -39,6 +57,10 @@ export class Center implements SmppSession {
 
 	private _defaultSingleJob!: Job;
 
+	get defaultSingleJob(): Job {
+		return this._defaultSingleJob;
+	}
+
 	set defaultSingleJob(value: Job) {
 		this._defaultSingleJob = value;
 		this.eventEmitter.emit(CenterEvents.STATE_CHANGED, this.serialize());
@@ -101,23 +123,60 @@ export class Center implements SmppSession {
 	}
 
 	sendMultiple(job: Job): Promise<void> {
-		throw new Error("NEBI");
+		return new Promise((resolve, reject) => {
+			this.validateSessions(reject);
+			if (!job.count || !job.perSecond) {
+				reject(`Center-${this._id} sendMultiple failed: invalid job, missing fields`);
+			}
+			this.logger.log1(`Center-${this._id} sending multiple messages: ${JSON.stringify(job)}`);
+
+			let counter = 0;
+			let previousUpdateCounter = 0;
+
+			this.counterUpdateTimer = new NanoTimer();
+			this.counterUpdateTimer.setInterval(() => {
+				if (previousUpdateCounter !== counter) {
+					this.eventEmitter.emit(ClientEvents.MESSAGE_SEND_COUNTER_UPDATE_EVENT, counter);
+					previousUpdateCounter = counter;
+				}
+			}, '', `${MESSAGE_SEND_UPDATE_DELAY / 1000} s`);
+
+			let count = job.count || 1;
+			let interval = 1 / (job.perSecond || 1);
+			this.sendTimer = new NanoTimer();
+			this.sendTimer.setInterval(() => {
+				if (count > 0 && counter >= count) {
+					this.cancelSendInterval();
+				} else {
+					this.sendPdu(job.pdu, true)
+						.catch(e => this.logger.log1(`Error sending message: ${e}`));
+					counter++;
+				}
+			}, '', `${interval} s`);
+			resolve();
+		});
 	}
 
 	sendMultipleDefault(): Promise<void> {
-		throw new Error("NEBI");
+		return this.sendMultiple(this.defaultMultipleJob);
 	}
 
 	sendPdu(pdu: object, force?: boolean): Promise<object> {
-		throw new Error("NEBI");
+		return new Promise((resolve, reject) => {
+			if (!force) {
+				this.validateSessions(reject);
+			}
+			this.logger.log5(`Center-${this._id} sending PDU: ${JSON.stringify(pdu)}`);
+			this.getNextSession().send(pdu, (replyPdu: object) => resolve(replyPdu));
+		});
 	}
 
 	sendSingle(job: Job): Promise<object> {
-		throw new Error("NEBI");
+		return this.sendPdu(job.pdu);
 	}
 
 	sendSingleDefault(): Promise<object> {
-		throw new Error("NEBI");
+		return this.sendPdu(this.defaultSingleJob.pdu);
 	}
 
 	serialize(): object {
@@ -135,6 +194,21 @@ export class Center implements SmppSession {
 		throw new Error("NEBI");
 	}
 
+	private validateSessions(reject: (reason?: any) => void) {
+		if (this.sessions.length === 0) {
+			reject(`No clients connected`);
+		}
+	}
+
+	private getNextSession(): any {
+		if (this.sessions.length === 0) {
+			return null;
+		}
+		let session = this.sessions[this.nextSession];
+		this.nextSession = (this.nextSession + 1) % this.sessions.length;
+		return session;
+	}
+
 	private eventBindTransciever(session: any, pdu: any) {
 		this.logger.log1(`Center-${this._id} got a bind_transciever with system_id ${pdu.system_id} and password ${pdu.password}`);
 		session.pause();
@@ -174,6 +248,7 @@ export class Center implements SmppSession {
 	private eventSessionClose(session: any): void {
 		this.logger.log1(`A client disconnected from center-${this._id}`);
 		this.sessions = this.sessions.filter((s: any) => s !== session);
+		this.nextSession = 0;
 		this.pendingSessions = this.pendingSessions.filter((s: any) => s !== session);
 		this.updateStatus();
 	}
diff --git a/src/Center/CenterPDUProcessor.ts b/src/Center/CenterPDUProcessor.ts
new file mode 100644
index 0000000..c7e22a4
--- /dev/null
+++ b/src/Center/CenterPDUProcessor.ts
@@ -0,0 +1,3 @@
+export interface CenterPDUProcessor {
+
+}
\ No newline at end of file
diff --git a/src/Client/Client.ts b/src/Client/Client.ts
index 3dd4f3c..747706a 100644
--- a/src/Client/Client.ts
+++ b/src/Client/Client.ts
@@ -35,7 +35,7 @@ export class Client implements SmppSession {
 
 		this.eventEmitter = new EventEmitter();
 		this.logger = new Logger(`Client-${id}`);
-		this.setStatus(ClientStatus.NOT_CONNECTED)
+		this.status = ClientStatus.NOT_CONNECTED;
 
 		this.initialize();
 	}
@@ -90,11 +90,6 @@ export class Client implements SmppSession {
 		return this.defaultMultipleJob;
 	}
 
-	setStatus(status: ClientStatus): void {
-		this._status = status;
-		this.eventEmitter.emit("status", status);
-	}
-
 	initialize(): void {
 		this.defaultSingleJob = Job.createEmptySingle();
 		this.defaultMultipleJob = Job.createEmptyMultiple();
@@ -112,10 +107,10 @@ export class Client implements SmppSession {
 			}
 
 			this.logger.log1(`Client-${this._id} connecting to ${this._url}`);
-			this.setStatus(ClientStatus.CONNECTING);
+			this.status = ClientStatus.CONNECTING;
 			this.connectSession().then(resolve, ((err: any) => {
 				this.logger.log1(`Client-${this._id} connection failed: ${err}`);
-				this.setStatus(ClientStatus.NOT_CONNECTED);
+				this.status = ClientStatus.NOT_CONNECTED;
 				this.session.close();
 				reject(err);
 			}));
@@ -130,7 +125,7 @@ export class Client implements SmppSession {
 			this.session.bind_transceiver({
 				system_id: this._username, password: this._password,
 			}, this.eventBindReply.bind(this));
-			this.setStatus(ClientStatus.BINDING);
+			this.status = ClientStatus.BINDING;
 		});
 		return this.bindPromise;
 	}
@@ -152,7 +147,7 @@ export class Client implements SmppSession {
 		return new Promise((resolve, reject) => {
 			this.logger.log1(`Client-${this._id} closing connection`);
 			this.session.close();
-			this.setStatus(ClientStatus.NOT_CONNECTED);
+			this.status = ClientStatus.NOT_CONNECTED;
 			resolve();
 		});
 	}
@@ -164,8 +159,7 @@ export class Client implements SmppSession {
 				this.validateBound(reject);
 			}
 			this.logger.log5(`Client-${this._id} sending PDU: ${JSON.stringify(pdu)}`);
-			this.session.send(pdu);
-			resolve(pdu);
+			this.session.send(pdu, (replyPdu: object) => resolve(replyPdu));
 		});
 	}
 
@@ -178,7 +172,7 @@ export class Client implements SmppSession {
 			}
 			this.logger.log1(`Client-${this._id} sending multiple messages: ${JSON.stringify(job)}`);
 
-			this.setStatus(ClientStatus.BUSY);
+			this.status = ClientStatus.BUSY;
 
 			let counter = 0;
 			let previousUpdateCounter = 0;
@@ -218,7 +212,7 @@ export class Client implements SmppSession {
 			this.sendTimer = null;
 			this.counterUpdateTimer = null;
 		}
-		this.setStatus(ClientStatus.BOUND);
+		this.status = ClientStatus.BOUND;
 	}
 
 	on(event: string, callback: (...args: any[]) => void): void {
@@ -253,7 +247,7 @@ export class Client implements SmppSession {
 
 	private eventSessionConnected(): void {
 		this.logger.log1(`Client-${this._id} connected to ${this._url}`);
-		this.setStatus(ClientStatus.CONNECTED);
+		this.status = ClientStatus.CONNECTED;
 		if (this.connectPromise) {
 			this.connectPromise.resolve();
 		}
@@ -266,26 +260,26 @@ export class Client implements SmppSession {
 
 	private eventSessionError(pdu: any): void {
 		this.logger.log1(`Client-${this._id} error on ${this._url}`);
-		this.setStatus(ClientStatus.NOT_CONNECTED);
+		this.status = ClientStatus.NOT_CONNECTED;
 		this.rejectPromises(pdu);
 	}
 
 	private eventSessionClose(): void {
 		this.logger.log1(`Client-${this._id} closed on ${this._url}`);
-		this.setStatus(ClientStatus.NOT_CONNECTED);
+		this.status = ClientStatus.NOT_CONNECTED;
 		this.rejectPromises();
 	}
 
 	private eventBindReply(pdu: any): void {
 		if (pdu.command_status === 0) {
 			this.logger.log1(`Client-${this._id} bound to ${this._url}`);
-			this.setStatus(ClientStatus.BOUND);
+			this.status = ClientStatus.BOUND;
 			if (this.bindPromise) {
 				this.bindPromise.resolve();
 			}
 		} else {
 			this.logger.log1(`Client-${this._id} bind failed to ${this.url}`);
-			this.setStatus(ClientStatus.CONNECTED);
+			this.status = ClientStatus.CONNECTED;
 			if (this.bindPromise) {
 				this.bindPromise.reject(pdu);
 			}
diff --git a/src/main.ts b/src/main.ts
index 8db138f..0319fc2 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -21,6 +21,7 @@ const app = express();
 const SERVER_PORT: number = Number(process.env.SERVER_PORT) || 8190;
 const WS_SERVER_PORT: number = Number(process.env.WS_SERVER_PORT) || 8191;
 const CENTER_SESSIONS_FILE: string = process.env.CENTER_SESSIONS_FILE || "center_sessions.json";
+const MESSAGE_SEND_UPDATE_DELAY: number = Number(process.env.MESSAGE_SEND_UPDATE_DELAY) || 500;
 
 // TODO: Add support for encodings
 // TODO: Implement some sort of metrics on frontend by counting the pdus