Cisco Cisco ONS 15454 SONET Multiservice Provisioning Platform (MSPP) Guía De Diseño

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A MAC address is a hardware address that physically identifies a network device.  The ONS 
15454 MAC forwarding table, will allow you to see all the MAC addresses attached to the enabled 
ports of an E-Series Ethernet card or an E-Series Ethernet Group.  This includes the MAC 
address of the network device attached directly to the Ethernet port and any MAC addresses on 
the ONS 15454 network linked to the port.  The MAC addresses table lists the MAC addresses 
stored by the ONS 15454 and the VLAN, Slot/Port/STS, and circuit that links the ONS 15454 to 
each MAC address. 
 

 
Hashing is an algorithm for organizing the MAC forwarding table.  In the E-Series cards, the hash 
table consists of approximately 1500 “buckets” with capacity for 5 MAC address entries in each 
bucket.  The hash algorithm reduces a MAC address to smaller pseudo-random index values 
used to streamline lookup performance.  In this scenario, MAC addresses that equate to the 
same hash value, post the first five learned entries for that index bucket, may not be included in 
the forwarding table; and therefore may not be recognized.  Frames destined for unknown MAC 
addresses are flooded.  Hashing is common practice and will most likely not be an issue in your 
applications, since proliferated MAC addresses are fairly random. 
 

 
The G-Series Ethernet cards support high bandwidth, low latency, point-to-point Gigabit Ethernet 
connectivity.  Each interface will negotiate for full-duplex operation and 802.3z flow control 
(asymmetric) with a maximum bandwidth of 1 Gb/s (2 Gb/s bi-directional) per port up to 2.5 Gb/s 
(5 Gb/s bi-directional) per card. The ONS 15454 G-Series include the following Ethernet cards: 
 

   G1000-4 

   G-1K-4 

 
The G1000-4 card supports bandwidth guarantees on a per port basis through the provisioning of 
SONET STS based  circuits between card ports.  You can map the four ports on the G1000-4 
independently to any combination of STS-1, STS-3c, STS-6c, STS-9c, STS-12c, STS-24c, and 
STS-48c circuit sizes, provided the sum of the circuit sizes that  terminate on a card do not 
exceed STS-48c. 
 
The G-Series cards provide up to 4 circuits and offer multiple protection capabilities, depending 
upon the users needs. The transported Gigabit Ethernet (Gig-E) circuits can be protected using 
SONET switching, Path Protection Configuration, BLSR, or PPMN; offering sub 50 ms restoration 
in the event of a transport network outage.  The “client” card interface may be protected by 
leveraging Gigabit EtherChannel or link aggregation protocols.  This allows you to provision two 
or more circuits between terminal devices, allowing these circuits to be routed over multiple G-
Series cards.  The Gig-E circuits can also be operated over unprotected OC-N spans. 
 
The new G-1K-4 card introduced in System Release 4.0, is a high density GE card.  It provides 
four GBIC interfaces.  The G-1K-4 card operates identically to the G1000-4 card, except the new 
card will interoperate with the XC or XC-VT cross-connect cards, when installed in the high-speed 
multi-service I/O slots (5, 6, 12, and 13).  Both, the G-1K-4 and G1000-4 cards can be installed in 
any multipurpose I/O slot when interoperating with the XC-10G cross-connect card.  The G-1K-4 
card is backward compatible to System Release 3.2 software.