I am having troubles on a Cisco Voice Gateway (3845) with the multilink 1 interface. This interface is connected via Cisco Unified Border Element (CUBE) for voice. At random times there is dead air when calling to the CUBE sites. I've ran some debugs and nothing is really coming up, not all calls experience this. Anyone ever run into this? Here is the sh version and sh int multilink 1 outputs.

Multilink1 is up, line protocol is up
Hardware is multilink group interface
Description: 4 T1 MLPPP bundle to MCI
Internet address is
MTU 1500 bytes, BW 6144 Kbit, DLY 100000 usec,
reliability 255/255, txload 15/255, rxload 4/255
Encapsulation PPP, LCP Open, multilink Open
Open: IPCP, loopback not set
Keepalive set (10 sec)
DTR is pulsed for 2 seconds on reset
Last input 00:00:00, output never, output hang never
Last clearing of "show interface" counters 1w1d
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 117
Queueing strategy: Class-based queueing
Output queue: 0/1000/64/117 (size/max total/threshold/drops)
Conversations 0/4/256 (active/max active/max total)
Reserved Conversations 2/2 (allocated/max allocated)
Available Bandwidth 3968 kilobits/sec
5 minute input rate 120000 bits/sec, 187 packets/sec
5 minute output rate 375000 bits/sec, 159 packets/sec
153788080 packets input, 3143856257 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
198 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
140087029 packets output, 2432655855 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
ORLmciRTR01#sh ver
Cisco IOS Software, 3800 Software (C3845-ENTSERVICESK9-M), Version 12.4(15)T3, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2008 by Cisco Systems, Inc.
Compiled Fri 25-Jan-08 00:11 by prod_rel_team
ROM: System Bootstrap, Version 12.3(11r)T2, RELEASE SOFTWARE (fc1)
ORLmciRTR01 uptime is 22 weeks, 3 days, 14 hours, 27 minutes
System returned to ROM by reload at 18:44:52 EDT Sat Apr 19 2008
System restarted at 18:46:22 EDT Sat Apr 19 2008
System image file is "flash:c3845-entservicesk9-mz.124-15.T3.bin"

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Cisco 3845 (revision 1.0) with 225280K/36864K bytes of memory.
Processor board ID FTX0936A3QS
2 Gigabit Ethernet interfaces
8 Serial interfaces
6 Channelized T1/PRI ports
DRAM configuration is 64 bits wide with parity enabled.
479K bytes of NVRAM.
62720K bytes of ATA System CompactFlash (Read/Write)
Configuration register is 0x2102