diff --git a/openbsc/include/openbsc/gsm_data.h b/openbsc/include/openbsc/gsm_data.h
index c27db85..b5f17ac 100644
--- a/openbsc/include/openbsc/gsm_data.h
+++ b/openbsc/include/openbsc/gsm_data.h
@@ -710,6 +710,7 @@
 	int T3115;
 	int T3117;
 	int T3119;
+	int T3122;
 	int T3141;
 
 	/* Radio Resource Location Protocol (TS 04.31) */
diff --git a/openbsc/src/abis_rsl.c b/openbsc/src/abis_rsl.c
index c076985..c27fff1 100644
--- a/openbsc/src/abis_rsl.c
+++ b/openbsc/src/abis_rsl.c
@@ -1152,6 +1152,45 @@
 
 #define GSM48_LEN2PLEN(a)	(((a) << 2) | 1)
 
+/* Format an IMM ASS REJ according to 04.08 Chapter 9.1.20 */
+static int rsl_send_imm_ass_rej(struct gsm_bts *bts,
+				unsigned int num_req_refs,
+				struct gsm48_req_ref *rqd_refs,
+				uint8_t wait_ind)
+{
+	uint8_t buf[GSM_MACBLOCK_LEN];
+	struct gsm48_imm_ass_rej *iar = (struct gsm48_imm_ass_rej *)buf;
+
+	/* create IMMEDIATE ASSIGN REJECT 04.08 message */
+	memset(iar, 0, sizeof(*iar));
+	iar->proto_discr = GSM48_PDISC_RR;
+	iar->msg_type = GSM48_MT_RR_IMM_ASS;
+	iar->page_mode = GSM48_PM_SAME;
+
+	memcpy(&iar->req_ref1, &rqd_refs[0], sizeof(iar->req_ref1));
+	iar->wait_ind1 = wait_ind;
+
+	if (num_req_refs >= 2)
+		memcpy(&iar->req_ref2, &rqd_refs[1], sizeof(iar->req_ref2));
+	else
+		memcpy(&iar->req_ref2, &rqd_refs[0], sizeof(iar->req_ref2));
+	iar->wait_ind2 = wait_ind;
+
+	if (num_req_refs >= 3)
+		memcpy(&iar->req_ref3, &rqd_refs[2], sizeof(iar->req_ref3));
+	else
+		memcpy(&iar->req_ref3, &rqd_refs[0], sizeof(iar->req_ref3));
+	iar->wait_ind3 = wait_ind;
+
+	if (num_req_refs >= 4)
+		memcpy(&iar->req_ref4, &rqd_refs[3], sizeof(iar->req_ref4));
+	else
+		memcpy(&iar->req_ref4, &rqd_refs[0], sizeof(iar->req_ref4));
+	iar->wait_ind4 = wait_ind;
+
+	return rsl_imm_assign_cmd(bts, sizeof(iar), (uint8_t *) iar);
+}
+
 /* MS has requested a channel on the RACH */
 static int rsl_rx_chan_rqd(struct msgb *msg)
 {
@@ -1197,7 +1236,9 @@
 		LOGP(DRSL, LOGL_NOTICE, "BTS %d CHAN RQD: no resources for %s 0x%x\n",
 		     msg->lchan->ts->trx->bts->nr, gsm_lchant_name(lctype), rqd_ref->ra);
 		counter_inc(bts->network->stats.chreq.no_channel);
-		/* FIXME: send some kind of reject ?!? */
+		/* FIXME gather multiple CHAN RQD and reject up to 4 at the same time */
+		if (bts->network->T3122)
+			rsl_send_imm_ass_rej(bts, 1, rqd_ref, bts->network->T3122 & 0xff);
 		return -ENOMEM;
 	}
 
diff --git a/openbsc/src/bsc_vty.c b/openbsc/src/bsc_vty.c
index a0c19b7..c293433 100644
--- a/openbsc/src/bsc_vty.c
+++ b/openbsc/src/bsc_vty.c
@@ -547,6 +547,7 @@
 	vty_out(vty, " timer t3115 %u%s", gsmnet->T3115, VTY_NEWLINE);
 	vty_out(vty, " timer t3117 %u%s", gsmnet->T3117, VTY_NEWLINE);
 	vty_out(vty, " timer t3119 %u%s", gsmnet->T3119, VTY_NEWLINE);
+	vty_out(vty, " timer t3122 %u%s", gsmnet->T3122, VTY_NEWLINE);
 	vty_out(vty, " timer t3141 %u%s", gsmnet->T3141, VTY_NEWLINE);
 	vty_out(vty, " dtx-used %u%s", gsmnet->dtx_enabled, VTY_NEWLINE);
 
@@ -1323,6 +1324,7 @@
 DECLARE_TIMER(3115, "Currently not used.")
 DECLARE_TIMER(3117, "Currently not used.")
 DECLARE_TIMER(3119, "Currently not used.")
+DECLARE_TIMER(3122, "Waiting time (seconds) after IMM ASS REJECT")
 DECLARE_TIMER(3141, "Currently not used.")
 
 DEFUN(cfg_net_dtx,