Raisecom RC802-30B-FV35 series User manual

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RC802-30B-FV35 Series
N×64K V.35 Interface
Fiber Optic Modem
User Manual
Raisecom Technology Co., Ltd.

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CONTENTS
CHAPTER 1. RC801-30B-FV35 INTRODUCTION.....................4
1.1 DESCRIPTION .........................................................................................错误！未定义书签。
1.2 PRODUCT SPECIFICATIONS.......................................................................................................4
1.2.1 Fiber Optic Interface Specification..................................................................................4
1.2.2 V.35 Interface Specification..............................................................................................4
1.2.3 V.35 Signal Bandwidth Engrossment of Timeslots at E1 Fractional Mode......................5
1.2.4 Power Supply ...................................................................................................................5
1.2.5 Ambience..........................................................................................................................5
1.2.6 Dimensions.......................................................................................................................5
1.3 EQUIPMENT INTERCONNECTION ..............................................................................................5
1.3.1 RC801-30B-FV35 Interconnection...................................................................................6
1.3.2 Interconnection with Other Modems................................................................................6
CHAPTER 2. RECOMMENDED CONNECTION TYPE......6
2.1 PRECAUTIONS BEFORE CONNECTION.......................................................................................6
2.1.1 Three Types of Timing Resource.......................................................................................6
2.1.2 Compatibility....................................................................................................................6
2.2 BASIC CONNECTION TYPE .......................................................................................................6
2.2.1 Point-to-point Fractional Mode, ‘Master Clock – Slave Clock’Topology.......................7
2.2.2 Point-to-point Fractional Mode, ‘Terminal Clock – Slave Clock’Topology....................7
2.2.3 Point-to-point Transparent Mode, ‘Master Clock – Master Clock’Topology..................8
EXTENDED CONNECTION TYPE .....................................................................................................8
CHAPTER 3. PREPARATION..........................................................................9
3.1 DESCRIPTION OF THE FRONT PANEL ........................................................................................9
3.1.1 Definition of the Indicators..............................................................................................9
3.1.2 V.35 (DCE) Interface......................................................................................................10
3.1.3 Fiber Optic Interface .....................................................................................................11
3.2 DIP-SWITCH SW1 SETUP ON THE BOTTOM PANEL.................................................................11
3.2.1 The 1st ~ 5th Bit: V.35 Interface Bandwidth Setup...........................................................11
3.2.2 The 6th Bit: V.35 Bandwidth Control Option ..................................................................12
3.2.3 The 7th and 8th Bits: Timing Resource Option ................................................................13
3.2.4 The Factory Default Setup of SW1: All OFF..........................................................13
3.3 DIP-SWITCH SW2 SETUP ON THE BOTTOM PANEL.................................................................13
3.3.1 The 1st ~ 6th Bits Definition ............................................................................................13
3.3.2 The 7th and 8th Bits: Vacant ............................................................................................15
3.3.3 The Factory Default Status of SW2: All OFF.................................................................15

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CHAPTER 4. INSTALLATIONAND
TROUBLESHOOTING..........................................................................................15
4.1 CAUTIONS BEFORE APPLYING THE POWER SUPPLY................................................................15
4.2 CONNECTION DIAGNOSIS ................................................................................................15
4.3 FAULT-PASS-THROUGH FUNCTION ...................................................................................16
4.4 FAQS...............................................................................................................................16

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Chapter 1. RC802-30B-FV35 Introduction
RC802-30B-FV35 series modular N*64kbps V.35 interface fiber optic modems are devices that
are deployed to transmit V.35 signals on fiber optics. They are widely used equipment in
constructing Wide Area Networks, and provide solutions for connecting Routers distantly.
RC802-30B-FV35 supports remote management function, and it can be deployed at the local site
to realize the remote management.
1.1 Main Features
1.2 Product Specifications
1.2.1 Fiber Optic Interface Specification
Bit rate: 100Mbps
Line code: 4B5B
Fiber connecter: SC
Optical Transmission of dual-strand fiber:
Transmit power: ≥-5 dBm
Receiving sensitivity: ≤-35 dBm
Transmit Wavelength: 1310nm
Distance: >40km
1.2.2 V.35 Interface Specification
Physical characteristics: Complies with V.35 interface standard
Connector type：ISO2593 female connector (34-pin female)
Working mode：DCE
Interface bit rate：V.35 interface bit rate is N×64Kbps（N=1~31）at E1 fractional
mode; V.35 interface bit rate is 2048Kbps at E1 transparent
mode

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1.2.3 V.35 Signal Bandwidth Engrossment of Timeslots at E1
Fractional Mode
The engrossment of timeslots in PCM31
In PCM31, N ≤31, No. 0 timeslot is taken up by the system.
TS[1] TS[N]
…… …… TS[31]
V.35 BANWIDTH
TS[0]
The engrossment of timeslots in PCM30
In PCM30, N ≤30, No. 0 and No. 16 timeslots are taken up by the system. N shall be counted
from No. 1 timeslot, and No. 16 timeslot shall be skipped if N is larger than 16.
TS[1] …… …… TS[31]
V.35 BANWIDTH
TS[N+1] …… TS[0] TS[16]
1.2.4 Power Supply
Power Supply: DC –48V, tolerance range from –36V to –72V
AC 220V, tolerance range from 165V to 265V
Power Consumption: ≤5W
1.2.5 Ambience
Working Temperature: 0 ~ 45℃
Relative Humidity: ≤90% (25℃)
1.2.6 Dimensions
Standalone equipment can be placed on the table.
Dimension: 142 (width) x 38 (height) x 178 (depth) mm
1.3 Equipment Interconnection
When connecting with other optical multiplexers, it is required to follow the instructions below.
Otherwise, link faults or abnormal data transmission may occur.

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1.3.1 RC801-30B-FV35 Interconnection
RC801-30B-FV35 series standalone dual-strand fiber optic modem shall work in pairs.
1.3.2 Interconnection with Other Modems
It is not suggested to connect RC801-30B-FV35 with other brand name N*64kbps V.35 interface
fiber optic modems through optical link, but RC801-30B-FV35 can work with Raisecom’s other
dual-strand fiber optic modems.
Chapter 2. Recommended Connection Type
2.1 Precautions before Connection
2.1.1 Three Types of Timing Resource
Master Clock Mode: The timing resource is provided by the crystal oscillator inside the
equipment, also called Internal Clock.
Slave Clock Mode: The timing resource is provided by recovering the clock from the fiber
optic receiving link, also called Restoring Clock.
Terminal Clock Mode: The timing resource is provided by the DTE, also called System
Clock.
2.1.2 Compatibility
If RC801-30B-FV35 is connected with G.703 interface fiber optic modem, and then connected
with other brand name E1 fractional mode equipment (i.e. V.35 to fractional E1 interface converter,
E1 interface Router); or such equipment as DXC and MUX is serially connected in the E1 link,
the following requirements shall be noticed.
1. PCM30/31 format must be the same
2. The status of CRC enable/disable function must be the same
3. The V.35 signal bandwidth engrossment of G.704 frame pattern must match
4. Ensure that there is only one timing resource in the whole link. Other PCM equipment shall
be configured to Slave Clock Mode (following the link clock).
2.2 Basic Connection Type
The connection topologies introduced in this part is only for user reference. Users are advised to

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design and deploy the most appropriate topology according to their specific environment.
2.2.1 Point-to-point Fractional Mode, ‘Master Clock – Slave
Clock’Topology
When connecting Routers or other V.35 interface equipment point to point, Routers shall work as
DTE. For the convenience of installation and test, it is advised to set the local modem ‘Master
Clock Mode’, and remote modem ‘Slave Clock Mode’. That is, the timing resource is from the
local modem.
2.2.2 Point-to-point Fractional Mode, ‘Terminal Clock –
Slave Clock’Topology
When the remote DTE must follow the timing resource of local DTE (the TX Clock is Internal
Clock in local DTE), it is advised to set the local RC801-30B-FV35 Terminal Clock, and remote
RC801-30B-FV35 Slave Clock Mode.

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2.2.3 Point-to-point Transparent Mode, ‘Master Clock –
Master Clock’Topology
When working at Transparent E1 Mode, both sides equipment can be set to Master Clock Mode.
The bit rate at V.35 interface will be 2048kbps.
Extended Connection Type
RC801-30B-FV35 cannot be interconnected with other brand name V.35 interface fiber optic
modems. However, users can adopt RC802-30B series E1 fiber optic modem, which will convert
the optical signals to G.703 compliant E1 electrical signals, and then, connect with a V.35 to
fractional E1 interface converter. Users can adopt Raisecom series interface converters such as
RC903-V35FE1 and RC904-V35FE1, and also other brand name interface converters.
RC801-30B-FV35
光缆
Router Router
V.35 DTE wire
E1
RC903-V35FE1
V.35 DTE wire
RC802-30B
If deploying E1 interface Router at the remote site, RC802-30B E1 fiber optic modem can be
adopted at the remote site as the following diagram. It is advised that if the Router is set to Master
Clock, then the RC801-30B-FV35 at local site shall be set to Slave Clock.

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RC801-30B-FV35 RC801-30B
光缆
Router
WAN port = V.35 Router
WAN port = E1
V.35 DTE wire E1
Chapter 3. Preparation
Please read this chapter carefully before installing the equipment.
3.1 Description of the Front Panel
LAL
RALPWR TX RX RLOS
LLOS LLOF
RLOF
LERR
RERR
DCE
RAISECOM RC800-30B-FV35 SERIES
3.1.1 Definition of the Indicators
PWR. Power supply indicator (green): Steady on, built-in power works in good condition.
LAL. Local receiving signal error alarm in optical link (red): ON, receiving signal error
occurs at local optical link (includeAIS, LOF and CRC).
RAL. Remote receiving signal error alarm in optical link (red): ON, receiving signal error
occurs at remote optical link (includeAIS, LOF and CRC).
LLOS. Local signal loss alarm in optical link (red): ON, when local receiving optical link is
disconnected.
RLOS. Remote signal loss alarm in optical link (red): ON, when remote receiving optical link
is disconnected.
LLOF. Local receiving loss of frame alarm in optical link (red): ON or flashing, when loss of
frame occurs in local receiving optical link.
RLOF. Remote receiving loss of frame alarm in optical link (red): ON or flashing, when loss
of frame occurs in remote receiving optical link.

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LERR. Local receiving bit error alarm in optical link (yellow): Flashing, when the bit error
rate exceed 10-3 in local receiving optical link; steady on and refreshes every other 10~20
seconds, when the bit error rate exceed 10-6.
RERR. Remote receiving bit error alarm in optical link (yellow): Flashing, when the bit error
rate exceed 10-3 in remote receiving optical link; steady on and refreshes every other 10~20
seconds, when the bit error rate exceed 10-6.
LAL and RAL indicators are used to check the E1 signals that are generated from the optical
receiving link. In the extended connection solutions in Chapter 2.3, if errors occur at the remote
transmit and receive link, then LAL and RAL can be used to indicate this alarm. If users do not
adopt Raisecom V.35 to fractional E1 interface converter (i.e. RC903-V35FE1), then the RAL
indicator is invalid.
3.1.2 V.35 (DCE) Interface
V.35 interface adopts V.35/ISO2593: DCE Connector Face – 34-pin Female connector. It can be
connected by standard DTE cable. The definitions of the pins are as follows:
Pin Name Input/Output Pin Number
Chassis Ground — CGND - A
Signal Ground — GND - B
Receive Data (A) — RD(A) O R
Receive Data (B) — RD(B) O T
Receive Timing (A) — RCK(A) O V
Receive Timing (B) — RCK(B) O X
Send Data (A) — TD(A) I P
Send Data (B) — TD(B) I S
Send Timing (A) — TCK(A) O Y
Send Timing (B) — TCK(B) O AA
Terminal Timing (A) — SCTE(A) I U
Terminal Timing (B) — SCTE(B) I W
Request to Send — RTS I C
Clear to Send — CTS O D
Data Set Ready — DSR O E
Data Carrier Detect — DCD O F
Data Terminal Ready — DTR I H
I --- input; O --- output.

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3.1.3 Fiber Optic Interface
For the dual-strand models, the fiber optic interface is DSC/PC. TX stands for optical signal
output (transmit); RX stands for optical signal input (receive).
3.2 Dip-switch SW1 Setup on the Bottom Panel
The dip-switch SW1 on the bottom panel must be set up before use.
1st ~ 5th bit: V.35 interface bandwidth setup
6th bit: bandwidth master control/slave control setup
7th ~ 8th bit: timing resource option
3.2.1 The 1st ~ 5th Bit: V.35 Interface Bandwidth Setup
V.35 bit rate is N*64kbps (N=1~31) when working at fractional E1 mode; V.35 bit rate is
2048kbps when working at transparent E1 mode. These 5 bits of the dip-switch are actually
representing the binary code of the N value. When N is configured to 0, RC801-30B-FV35 is
working at transparent E1 mode.
1st bit 2nd bit 3rd bit 4th bit 5th bit Bandwidth (bit/s)
0 0 0 0 0 2048K (transparent E1 mode)
0 0 0 0 1 1×64K=64K (minimum bandwidth)
0 0 0 1 0 2×64K=128K
0 0 0 1 1 3×64K=192K
0 0 1 0 0 4×64K=256K
0 0 1 0 1 5×64K=320K
0 0 1 1 0 6×64K=384K
0 0 1 1 1 7×64K=448K
0 1 0 0 0 8×64K=512K
0 1 0 0 1 9×64K=576K
0 1 0 1 0 10×64K=640K
0 1 0 1 1 11×64K=704K
0 1 1 0 0 12×64K=768K
1 2 3 4 5 6 7 8
ON
OF

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0 1 1 0 1 13×64K=832K
0 1 1 1 0 14×64K=896K
0 1 1 1 1 15×64K=960K
1 0 0 0 0 16×64K=1024K
1 0 0 0 1 17×64K=1088K
1 0 0 1 0 18×64K=1152K
1 0 0 1 1 19×64K=1216K
1 0 1 0 0 20×64K=1280K
1 0 1 0 1 21×64K=1344K
1 0 1 1 0 22×64K=1408K
1 0 1 1 1 23×64K=1472K
1 1 0 0 0 24×64K=1536K
1 1 0 0 1 25×64K=1600K
1 1 0 1 0 26×64K=1664K
1 1 0 1 1 27×64K=1728K
1 1 1 0 0 28×64K=1792K
1 1 1 0 1 29×64K=1856K
1 1 1 1 0 30×64K=1920K (Max bandwidth 1)
1 1 1 1 1 31×64K=1984K (Max bandwidth 2)
In the above table, ‘1’ stands for OFF status of the switch, and ‘0’ stands for ON status. For
example, the binary code corresponding to 384kbps bandwidth is ‘00110’. Then, the switches shall
be set to ‘ON, ON, OFF, OFF, ON’. When doing this, users are advised to note down the binary
code corresponding to the required bandwidth, then refer to the above table for switch status.
‘Max bandwidth 1’is the maximum bandwidth in PCM30.
‘Max bandwidth 2’is the maximum bandwidth in PCM31.
3.2.2 The 6th Bit: V.35 Bandwidth Control Option
6th bit Bandwidth Control Option
OFF Master Control
ON Slave Control
The following conditions shall be satisfied in order to realize the remote bandwidth control
function.
1. RC801-30B-FV35 series modems are deployed point to point, and in pairs.
2. There is no PCM equipment (i.e. DXC, MUX) that takes up the No. 0 timeslot in the link.
3. Neither of the RC801-30B-FV35 at both sides shall be set to transparent mode (N is not 0).
When all the conditions are met, user can set Master Control at one site, and Slave Control at the
other site. The first 5 bits switches can be set to all OFF. After the link is established, the actual
bandwidth at Slave Control site is the same as the Master Control site. Please note that neither of
the both sites can be set to transparent mode (N=0).
This bit switch has nothing to do with the timing resource. Users can either set Master Control at

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the Master Clock site, or at the Slave Clock site.
If any of the three conditions cannot be met, then both modems shall be set to Master Control and
the first 5 bits will be used to configure the actual bandwidth. Please note that when N=0, the
equipment is working at transparent mode and this bit switch is invalid.
3.2.3 The 7th and 8th Bits: Timing Resource Option
7th bit 8th bit Timing Resource Option
OFF OFF Master Clock (Internal)
OFF ON V.35 Terminal Clock
ON OFF Vacant
ON ON Slave Clock (follow the link clock)
Users are advised to select the most suitable timing resource according to the connection types in
Chapter 2. When configuring the timing resource, V.35 DTE interface on Routers shall also be
configured. Both TX and RX clock shall be External Clock mode at V.35 interface that connected
with Master/Slave Clock equipment. The TX Clock shall be Internal Clock mode and RX Clock
shall be External Clock mode at the V.35 interface that connected with Terminal Clock equipment.
3.2.4 The Factory Default Setup of SW1: All OFF
Switch 1st bit 2nd bit 3rd bit 4th bit 5th bit 6th bit 7th bit 8th bit
Default OFF OFF OFF OFF OFF OFF OFF OFF
Details N=31，V.35 bandwidth 1984K
Bandwidth
Master
Control
Master Clock
Mode
3.3 Dip-switch SW2 Setup on the Bottom Panel
3.3.1 The 1st ~ 6th Bits Definition
1st bit 2nd bit 3rd bit 4th bit 5th bit 6th bit
Definition TX CLK
phase
RX CLK
phase
PCM30/31
Option
CRC
function
option
Loop-back
test
Loop-back
option
ON Negative Negative PCM30 Disable Loop-back
Local

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Loop-back
OFF Positive Positive PCM31 Enable Normal
Remote
Loop-back
Since the relationships between V.35 data and clock phase are different on different brand
Routers, TX CLK and RX CLK phase options are used to solve the problem. When TX CLK
and RX CLK are both set to Positive, the RC801-30B-FV35 modem has passed the test at the
V.35 synchronous WAN interface of CISCO series Routers.
TX CLK positive: TD signal will be sampled at the falling edge of TCK clock signal
TX CLK negative: TD signal will be sampled at the rising edge of TCK clock signal
RX CLK positive: RD signal will be sampled at the falling edge of RCK clock signal
RX CLK negative: RD signal will be sampled at the rising edge of RCK clock signal
PCM30/31 option. When other equipment (i.e. DXC, MUX) in the link requires the frame
format to be PCM30, the modem shall be configured to PCM30 (N≤30); when requires the
frame format to be PCM31, the modem shall be configure to PCM31 (N≤31). The local and
remote sites shall have the same configuration.
CRC option. Disable/Enable the CRC function according to the link requirement. The local
and remote sites shall have the same configuration.
Loop-back test is the auxiliary function used for users to test and diagnose the equipment and
link.
Local Loop-back is performed at local V.35 interface and used for test and diagnosis the V.35
interface.
The local V.35 interface loop-back can only performed on the ‘Master Clock’ and ‘Terminal
Clock’ equipment. As the above figure, the local equipment is set to Master Clock or Terminal
Clock mode. The 5th and 6th bits of SW2 are switched to ON, and the 1st ~ 5th bits are set to
configure the customized bandwidth. The loop-back status can be viewed at the port of local
Router.
Remote loop-back is performed at the optical interface on remote equipment to test and diagnose
the optical link. In order to perform the remote loop-back at optical interface, 2 conditions must be
satisfied.
1. RC801-30B-FV35 modems work point to point, and in pairs (or RC802-30B series E1 fiber
optic modem at the remote site).
2. The test can only be performed on the ‘Master Clock’and ‘Terminal Clock’equipment.
As the above figure, the local equipment is set to Master Clock or Terminal Clock mode. The 5th
bit is switched to ON, and the 6th bit is switched to OFF. If the optical fiber is connected properly,
the loop-back status can be viewed at the port of local Router.

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3.3.2 The 7th and 8th Bits: Vacant
These two bits are vacant and reserved for further use.
3.3.3 The Factory Default Status of SW2: All OFF
Switch 1st bit 2nd bit 3rd bit 4th bit 5th bit 6th bit 7th bit 8th bit
Status OFF OFF OFF OFF OFF OFF OFF OFF
Definition TX CLK
positive
RX CLK
positive PCM31 CRC
Enable
Not
loop-back
Remote
loop-back Vacant
Chapter 4. Installation and Troubleshooting
This chapter is for the reference for technical person. If it is the first time using this equipment,
please carefully read Chapter 3 first.
4.1 Cautions before Applying the Power Supply
It is strictly forbidden to hot-swap the V.35 interface cable.
If adopts the DC –48V power supply, please first connect the Protecting Ground (the middle
pin); then the 0V pin (the right pin, high electrical potential); at last the –48V pin (left pin,
low electrical potential). They must not be reversely connected.
4.2 Connection Diagnosis
LERR or RERR indicator may be ON when just after connecting the optical fiber. This is because
a few error bits are generated by connecting cables. LERR and RERR indicators shall be OFF in
10~20 seconds.
Check if there is any alarm on local equipment
Test if data communication can be performed between local DTE and remote equipment
If the test is failed, please try the following steps.
1. Local V.35 interface loop-back. Refer to previous dip-switch setup for details. If the Router
indicates loop-back successful, the V.35 interface is working in good condition. If the Router
indicates loop-back fails, please first check the timing resource and bandwidth setup at local
site, and try to adjust the TX CLK and RX CLK phase option switch.
2. After the success of the first step, check if the optical link works in good condition. If
RC801-30B-FV35 modems work in pairs (or adopts RC802-30B-FV35 at the remote site),
users are advised to perform the remote loop-back test. The local Router shall indicate if the
remote loop-back in optical link is successful.

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3. If the modem is not working in pairs, it is required that the other brand equipment be
configured exactly the same as the local modem, including PCM30/31 format, CRC
enable/disable, and timing resource etc. If these parameters are properly configured, then
please pay attention to the V.35 data engrossment in frame format. Refer to Chapter 1.3.4 for
timeslot engrossment and ensure that both equipments have the same configuration.
4. After success of the second step (or ensure the 3rd step), it is indicated that the
communication link between local and remote equipments is working properly. Now, if the
remote V.35 interface is connected properly but still cannot communicate normally, please
adjust the TX CLK or RX CLK phase option on remote modem (or converter).
If the link still remains disconnected, please contact the technical support from the local
distributors. It is strongly suggested users present a report of the encountered problems along with
network topology, and the test details of the above four steps, and email the report to the technical
support.
4.3 Fault-pass-through Function
If LAL alarm appears, DCD signals will be disconnected at V.35 interface, and the DTE shall
response that.
If RAL alarm appears, CTS signals will be disconnected at V.35 interface, and the DTE shall
response that.
4.4 FAQs
If there is any problem during installation and operation, please try the following solutions. If the
problems still cannot be solved, please contact distributors for technical support.
Local Alarm Indicator is ON.
Answer: It is possible that there is uplink alarm (AIS), loss of frame (LOF), or CRC alarm
appearing on the modem. It indicates that the signal received is abnormal. Please check the link
quality and interface parameter at the remote site.
Remote Alarm Indicator is ON.
Answer: It is because there is receiving alarm at the remote site. The signal is send by the remote
interface converter RC903-V35FE1.
Optical Interface LLOS (RLOS) is ON.
Answer: Receiving signal at optical interface is lost. Please check if the optical input (RX) is
connected, or reversely connected. Users can use the optical power meter to test the receiving
optical power to check if it is above the threshold of optical receiving sensitivity.
Optical Interface LLOF (RLOF) is ON.
Answer: Optical receiving signal is loss of frame. Optical signals are receiving but the optical
power may be around the threshold. Please check the receiving optical power. If connects modem

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of different brand name at optical interface, there also may be LLOF alarm.
Optical Interface LERR (RERR) is ON.
Answer: When flashing, the bit error rate of optical signal is above 10-3. Please check if the optical
interface is connected properly, or the receiving optical power, and also ensure there is no sharp
turn of the optical fiber. When steady on, the bit error rate of optical signal is above 10-6. This
alarm may be appearing just after applying the power supply, which is normal phenomenon, and it
shall be off in 10 seconds. If the indicator is steady on during operation, please check if the optical
interface is connected properly and the receiving optical power.
Severe packet loss of DTE equipment
Answer: The possible reasons for severe packet loss are：
1．Incorrect timing resource setup
2．Check V.35 interface status of the Router, if there are data errors on input and output, then it
indicates that TX CLKand RX CLK phase relationship need to be adjusted. This problem can
be located by performing local V.35 interface loop-back test.
3．Cable loose.
Compatibility with similar equipment of other brands
Answer: Raisecom RC801-30B-FV35 cannot cooperate with similar products of other brands. It is
because the signal coding and protocols at optical interface are different. However, users can refer
to Chapter 2.3 for details of extended connection types.
Compatibility with other Raisecom V.35 interface equipment
Answer: RC801-30B-FV35 can cooperate with other Raisecom V.35 interface equipments that
have similar functions, such as followings:
1. RC903-V35FE1 standalone V.35 to fractional E1 interface converter
2. RC904-V35FE1 modular V.35 to fractional E1 interface converter
3. SUBM-FV35 N*64kbps V.35 interface expansion module that installed into
RC801-240B series standalone fiber optic multiplexer.

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