1 Hardware Description

78-5296-02 10/02/98

Figure 1-5

NTC OC-3 Application

ATM on

OC-3c

NTC

Downstream

data

transfer

Optical

interface

Upstream

data

transfer

Cisco

6200

Line

module

12688

The optical interface performs the optical-to-electrical and electrical-to-optical conversions. Its other tasks include clock recovery, overhead processing, cell delineation, and diagnostic information retrieval.

The upstream data transfer unit receives data via a 16-bit parallel input from the internal bus on the node’s backplane. ATM cells are received from an SLC channel only after that channel has won access to the upstream data bus from the other contending line channels. The upstream data transfer unit monitors the contention bus to direct inbound data to the optical interface.

The downstream data transfer unit inserts data onto the bus. This circuit inserts idle cells when a full data cell is not yet ready for transmission.

1.3.2 NTC OC-3: Physical Description

The NTC resides in slot 1 (the left-most slot as you face the front of the chassis). Each OC-3 NTC faceplate is marked NTC OC3-SM (single-mode) or NTC OC3-MM (multimode). The faceplate (see Figure 1-6) includes the fixtures discussed in the following paragraphs.

OC-3c Trunk Port

The dual SC connectors (one for transmitting, one for receiving) for the Cisco 6200 network trunk port are recessed into the OC-3 NTC faceplate to prevent the cables from protruding too far outside the faceplate.

Warning Class 1 laser product.

Warning Because invisible laser radiation may be emitted from the aperture of the port when no cable is connected, avoid exposure to laser radiation and do not stare into open apertures.

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Cisco Systems 6200 appendix NTC OC-3 Physical Description, OC-3c Trunk Port