WAN

Why T1 bandwidth shows 1536 for T1 interface on Cisco router?

2010-03-31T21:23:36Z

You might see bandwidth indication on your T1 link shows 1536Mbps instead of 1544Mbps. The number implies data portion of frames.

As you know T1 is divided into 8000 frames per second and each frame has 192bits for data frames + 1bit for framing bit. So without framing bit, data portion of frames will be 8000(pe second) x 192bits = 1536000 BPS.

T1 speed = 1.544Mbps = 193bits x 8000 (frames)

Without framing bits(Payload) = 1.536Mbps = 192bits x 8000(frames)

Also, you might see bandwidth of DS3 is shown as 44210 Kbps

DS3 bandwidth = 44,736,000 bps - 526,306 bps(overhead) = 44,209,694 bps = 44210 kbps

Extra >

There are three different types of T1s

1. Unchannelized T1
2. Channelized T1 and
3. ISDN PRI

A single T1 frame format = 193 bits = 192 bits(24 x 8 bits) + 1 framing bit
** 24 x DS0, each DS0 has 8 bits.

Unchannelized T1 = 1.544Mbps = 193 bits x 8000 frames

Channelized T1 = 1.544Mbps = [ 64Kbps x 24(time slot) ] + 8000 (framing bit)

64Kbps = 56Kbps + 8kbps (signaling)
** 56Kbps = 7 bit (payload) x 8000 frames

SONET / SDH Technical information

2010-03-14T21:52:34Z

What is SONET & SDH?

SONET and SDH are a set of related standards for synchronous data transmission over fiber optic networks. SONET stands for Synchronous Optical Network and SDH is short for Synchronous Digital Hierarchy. SONET is the United States version of the standard published by the American National Standards Institutue (ANSI). SDH is the international version of the standard published by the International Telecommunications Union (ITU).

Speed

OC stands for Optical Carrier
STS stands for Synchronous Transport Signal

**SONET/SDH Speed**
Optical Level	Electrical Level	Line Rate (Mbps)	Payload Rate (Mbps)	Overhead (Mbps)	SDH Equivalent
OC-1	STS-1	51.84	50.112	1.728	-
OC-3	STS-3	155.52	150.336	5.184	STM-1
OC-12	STS-12	622.08	601.344	20.736	STM-4
OC-48	STS-48	2488.32	2405.376	82.944	STM-16
OC-192	STS-192	9953.28	9621.504	331.776	STM-64
OC-768	STS-768	39813.12	38486.016	1327.104	STM-256

What is Clear Channel or channelized?

Clear channel means the entire payload rate is available as a single channel of communications or flow of packet or cell.
The opposite of clear channel is "channelized". In a channelized link the payload rate is subdivided into multiple fixed rate channels.

Light level information for Cisco 12000 SONET modules

2010-03-05T20:06:08Z

Check this URL to see all light level of Cisco module

http://www.cisco.com/en/US/products/hw/modules/ps5455/prod_module_series_home.html

===========
CISCO 12008
===========

4-port OC-3/STM-1 ATM/SDH MM LC w/SC ( 4OC-3-ATM-MM-SC )

-14 to -18.5 dBm transmit power
-14 to -30 dBm receive sensitivity

Wavelength 1300 nm

4-port OC-3/STM-1 ATM/SDH SM IR LC w/SC ( 4OC-3-ATM-IR-SC )

-8 to -15 dBm transmit power
-8 to -31 dBm receive sensitivity

Wavelength 1300 nm

8-port OC-3/PoS line card w/MM Interface, MTRJ ( 8OC3/POS-MM ) 16-port OC-3/PoS line card w/MM Interface, MTRJ ( 16OC3/POS-MM )

-14 to -18.5 dBm transmit power
-14 to -30 dBm receive sensitivity

Wavelength 1261 to 1360 nm

8-port OC-3/PoS line card w/SM interface, LC ( 8OC3/POS-SM ) 16-port OC-3/PoS line card w/SM interface, LC ( 16OC3/POS-SM )

-8 to -15 dBm transmit power
-8 to -28 dBm receive sensitivity

Wavelength 1261 to 1360 nm

4-port OC-3/STM-1 SONET/SDH MM LC w/SC ( LC-4 OC-3-POS-MM )

-14 to -18.5 dBm transmit power
-14 to -30 dBm receive sensitivity

Wavelength 1261 to 1360 nm

4-port OC-3/STM-1 SONET/SDH SM IR LC w/SC ( LC-4 OC-3-POS-SM )

-8 to -15 dBm transmit power
-8 to -31 dBm receive sensitivity

Wavelength 1261 to 1360 nm

4-port OC-3/STM-1 SONET/SDH SM LR LC w/SC ( 4OC-3-POS-LR-SC )

0 to -5 dBm transmit power
-8 to -34 dBm receive sensitivity

Wavelength 1280 to 1335 nm

1-port OC-12/STM-4 ATM/SDH MM LC w/SC ( LC-1OC12-ATM-MM )

-14 to -20 dBm transmit power
-14 to -26 dBm receive sensitivity

Wavelength 1300 nm

1-port OC-12/STM-4 ATM/SDH SM LC w/SC ( LC-1OC12-ATM-SM )

-8 to -15 dBm transmit power
-8 to -28 dBm receive sensitivity

Wavelength 1300 nm

4-port Channelized OC-12/STM-4 ( DS3/E3, OC-3c/STM-1c )POS/SDH ISE SM w/SC ( 4CHOC12/DS3-I-LCB )

-8 to -15 dBm transmit power
-8 to -28 dBm receive sensitivity

Wavelength 1310 nm

1-port OC-12/STM-4 SONET/SDH MM LC w/SC ( LC-1OC12-POS-MM ) 4-port OC-12/STM-4 SONET/SDH MM w/SC ( 4OC12E/POS-MM-SC )

-14 to -20 dBm transmit power
-14 to -26 dBm receive sensitivity

Wavelength 1270 to 1380 nm

1-port OC-12/STM-4 SONET/SDH SM IR LC w/SC ( LC-1OC12-POS-SM ) 4-port OC-12/STM-4 SONET/SDH SM IR w/SC ( 4OC12E/POS-IR-SC )

-8 to -15 dBm transmit power
-8 to -28 dBm receive sensitivity

Wavelength 1270 to 1380 nm

1-port Channelized OC-48/STM-4 ( DS3/E3, OC-3c/STM-1c, OC-12c/STM-4c )POS/SDH ISE SM w/SC ( CHOC48/DS3-SRI-SC )

-3 to -10 dBm transmit power
0 to -18 dBm receive sensitivity

Wavelength 1310 nm

1-port OC-48c/STM-16c SONET/SDH SM Enhanced 1310nm SR w/SC ( OC48E/POS-SR-SC ) 1-port OC-48c/STM-16c SONET/SDH SM Enhanced 1310nm SR w/FC ( OC48E/POS-SR-FC ) 1-port OC-48c/STM-16c SONET/SDH SM 1310nm SR w/SC ( OC48E/POS-SR-SC-B ) 1-port OC-48c/STM-16c SONET/SDH SM 1310nm SR w/FC ( OC48E/POS-SR-FC-B )

-3 to -10 dBm transmit power
0 to -18 dBm receive sensitivity

Wavelength 1310 nm

1-port OC-48c/STM-16c SONET/SDH SM Enhanced 1550nm LR w/SC ( OC48E/POS-1550-SC ) 1-port OC-48c/STM-16c SONET/SDH SM Enhanced 1550nm LR w/FC ( OC48E/POS-1550-LC ) 1-port OC-48c/STM-16c SONET/SDH SM 1550nm LR w/SC ( OC48E/POS-LR-SC-B ) 1-port OC-48c/STM-16c SONET/SDH SM 1550nm LR w/SC ( OC48E/POS-LR-FC-B )

+3 to -2 dBm transmit power
-9 to -28 dBm receive sensitivity

Wavelength 1550 nm

4-port OC-48c/STM-16c SONET/SDH SM SR w/SC ( 4OC-48/POS-SR-SC ) 4-port OC-48c/STM-16c SONET/SDH SM SR w/FC ( 4OC-48/POS-SR-FC )

-3 to -10 dBm transmit power
0 to -18 dBm receive sensitivity

Wavelength 1,310 nm

4-port OC-48c/STM-16c SONET/SDH LR w/SC Part# 4OC-48/POS-LR-SC (SM) 4-port OC-48c/STM-16c SONET/SDH LR w/FC Part# 4OC-48/POS-LR-FC (SM)

+3 to -2 dBm transmit power
-9 to -28 dBm receive sensitivity

Wavelength 1,550 nm

1-port OC192c/STM64c POS Line Card 1310 nm SR, w/SC Part# OC192/POS-SR-SC(SM)

-1 to -6 dBm transmit power
-1 to -11 dBm receive sensitivity

Wavelength 1,310 nm

1-port OC192c/STM64c POS Line Card 1550 nm IR, w/SC Part# OC192/POS-IR-SC (SM)

+2 to -1 dBm transmit power
+3 to -14 dBm receive sensitivity

Wavelength 1,550 nm

1-port OC192c/STM64c POS Line Card 850 nm VR, w/CC Part# OC192/POS-VR(SM)

-3 to -10 dBm transmit power
-3 to -16 dBm receive sensitivity

Wavelength 850 nm

How enable scramble on Cisco SONET interface

2010-03-05T19:49:51Z

Scrambling for POS interfaces is set on the interface itself. It is not a controller option..

Cisco Router# sho int pos5/1
POS5/1 is up, line protocol is up
Hardware is PM5351 S/UNI-TETRA-155 Framer
MTU 4470 bytes, BW 155000 Kbit, DLY 100 usec,
reliability 255/255, txload 56/255, rxload 49/255
Encapsulation FRAME-RELAY, crc 16, loopback not set
Keepalive set (10 sec)
Scramble enabled

Command Syntax

To Enable Scrambling:

Cisco Router(config)#int pos5/1
Cisco Router(config-if)#pos scramble-atm

To Disable Scrambling:

Cisco Router(config)#int pos5/1
Cisco Router(config-if)#no pos scramble-atm

SONET Graphical Overview

2010-03-05T19:41:26Z

This is very useful documentation for SONET basic 101.

Must see if you are learning SONET or refresh your SONET knowledge.

http://www.cisco.com/en/US/tech/tk482/tk607/technologies_tech_note09186a0080124afa.shtml

CSU/DSU alarms indications

2009-10-08T03:38:07Z

When you are troubleshooting Telco circuit, DSU/CSU alarm indication is important fact to isolate an issue without wasting time. The most common alarms are Red, Yellow and Blue (as known as AIS - Alarm Indication Signal) alarm.

Red Alarm

A Red alarm indicates CSU/DSU has lost synchronization over a longer period of time. It could be a lost of signal or frame error occurred. Frame errors are normally happening when two or more framing bit errors within a 3 ms period.

A device declares red alarm condition when above errors are detected. After that the device will send Yellow alarm to far-end device.

Yellow Alarm

A device has declared red alarm condition, and sends yellow alarm to far-end. If far-end device received the yellow alarm, it means a circuit from the device that received red alarm to far-end device is fine. For example, there are two devices on the circuit; A and B. Let's say device B is receiving lost signal or out of frame errors from the circuit, the device B will declare Red alarm indication on the port that is connected to device A. The device B will send yellow alarm to far-end device which is device A. If the device A received the yellow alarm, transport link is fine from device B to A, but not other way around.

Blue Alarm or AIS(Alarm Indication Signal)

Blue Alarm or AIS(Alarm Indication signal) indicates that a device receiving continuous unframed 1s. It caused by a segment of the end-to-end link failed at a logical or physical level while direct link is okay.

How to calculate full mesh WAN links

2009-09-16T01:51:47Z

There are three different type of network topologies.

1. Hub-and-spoke

2. Full mesh

3. Hybrid

How to calculate WAN links?

Here is how to calculate the number of links in hub-and-spoke and full mesh networks

S = number of Site
L = number of link

Hub-and-spoke : L = S -1

ex) 6 sites for number of links for 5

Full mesh : L = S(S-1)/2

ex) 6 sites for number of links for 15

Hybrid networks can be arranged in any fashion that best fits the needs of services, so there are no predictable shape for the number of link required.

NSE and PSE on SONET interface

2009-05-25T03:37:06Z

Question;

Hi,

I saw NSE and PSE counts are increasing big time on our SONET interface. My Cisco has 1 OC12 POS controller with 12.2 IOS.
I could ignor the event if fews per days, but it is a lot.

WestRouter#sh controllers pos 1/0
POS1/0
SECTION
LOF = 0 LOS = 0 BIP(B1) = 0
LINE
AIS = 0 RDI = 0 FEBE = 0 BIP(B2) = 0
PATH
AIS = 0 RDI = 0 FEBE = 0 BIP(B3) = 0
LOP = 0 NEWPTR = 0 PSE = 11877 NSE =12577

Any advice would be appreciate.

we set clocking source "line" on both (ISP said that they set clocking source "line")

Answer:

In general, NSE and PSE would be due to clocking source issue. Have you check both interfaces are set to "line".
Unless your SONET is connected to both routers in back to back, clocking source will be provided by SONET Ring.
Best way is to work with telco, and test to loops stepping out from our router since that is where we are seeing the issue.

Check the below link to get more info.
http://www.cisco.com/en/US/tech/tk482/tk607/technologies_tech_note09186a008009464b.shtml

That's good.
From what I've seen in the past on your interface, you will not see any impact to traffic unless the PSE/NSE's are updating by the thousands every second. The Cisco web page advises that a stratum 3 timed-device allows for up to 59.6 stuffs per second.

The NSE & PSE only indicate that the payload has shifted within the SONET frame. This does not impact customer data.

Check this one out for more information for a decent explanation of stuff events.
http://www.cisco.com/en/US/partner/tech/tk482/tk607/technologies_tech_note09186a008009464b.shtml

PSE and NSE counters will be increased below conditions

- The received signal is very degraded.
- There are sufficient differences in the accuracy of the oscillator at each end
- The physical fiber is not clean
- The transmitter is overdriving the remote receiver and there is insufficient attenuation on the link
- Errored condition

Per Cisco, Cisco router is not generated PSE and NSE event.

[Cisco] MLPPP sample configuration

2009-05-05T15:04:05Z

Here is the sample configuration for MLPPP (Multi Link PPP) on Cisco 12008

interface Multilink1
description : customer.com:MLPPP
ip unnumbered Loopback0
mtu 1500
no ip redirects
no ip directed-broadcast
no ip proxy-arp
no ip mroute-cache
no peer neighbor-route
ppp multilink
multilink-group 1
!
interface Serial3/0/1:0
description : customer.com:MLPPP
no ip address
mtu 1500
encapsulation ppp
ppp multilink
multilink-group 1
!
interface Serial3/1/1:0
description : customer.com:MLPPP
no ip address
mtu 1500
encapsulation ppp
ppp multilink
multilink-group 1

Cisco 3700 DS3 DSU mode option

2009-05-05T15:01:29Z

If DSU mode is not matched with other side, it might cuase intermittent error or synchonization issue. You must know what type of DSU is connected to the remote port to determine if it interoperates with an E3 or T3 controller or a PA-E3 or PA-T3 port adapter. To improves interoperability, The local interface configuration must match the remote interface configuration. For example, if you define the data service unit (DSU) interoperability mode as 1 on the local port, you must also do the same on the remote port.

DSU mode optioin

Option 0

Sets the interoperability mode to 0. This is the default. Specify mode 0 to connect an E3 controller to another E3 controller or to a Digital Link DSU (DL3100). Specify mode 0 to connect a PA-E3 port adapter to another PA-E3 port adapter or to a Digital Link DSU (DL3100). Use mode 0 to connect a PA-T3 port adapter to another PA-T3 port adapter or to a Digital Link DSU (DL3100).

EX)Cisco PAT3 / E3 or controller <---> Cisco PAT3
Cisco PAT3 / E3 or controller <---> Digital Link (DL3100)

Option 1

Sets the interoperability mode to 1. Specify mode 1 to connect an E3 or T3 controller or a PA-E3 or PA-T3 port adapter to a Kentrox DSU.

Option 2

Sets the interoperability mode to 2. Specify mode 2 to connect a T3 controller or a PA-T3 port adapter to a Larscom DSU.

Option 3

Sets the interoperability mode to 3. Specify mode 3 to connect a T3 controller to an Adtran T3SU 300.

Option 4

Sets the interoperability mode to 4. Specify mode 4 to connect a T3 controller to a Verilink HDM 2182.

WAN