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Ethernet Card Software Feature and Configuration Guide, R7.2
January 2009
Chapter 23 E-Series and G-Series Ethernet Operation
G-Series Manual Cross-Connects
On the ONS 15454 and ONS 15327, provisionable SONET circuit sizes are STS 1, STS 3c, STS 6c, STS
9c, STS 12c, STS 24c, and STS 48c. On the ONS 15454 SDH, provisi onable SDH circuits are VC4,
VC4-2c, VC4-3c, VC4-4c, VC4-8c, and VC4-16c. Each Ethernet port maps to a unique STS/VC circuit
on the G-Series card.
Figure 23-4 G-Series Point-to-Point Circuit
The G-Series supports any combination of up to four circuits from t he list of valid circuit sizes; however,
the circuit sizes can add up to no more than 48 STSs or 16 VC4s.
Due to hardware constraints, the card imposes an additiona l restriction on the combinations of circuits
that can be dropped onto a G-Series card. These restrictions are transparently enforced by the node, and
you do not need to keep track of restricted circuit combinations.
When a single STS-24c/VC4-8c terminates on a card, the remaining circuits on that card can be another
single STS-24c/VC4-8c or any combination of circuits of STS-12c/VC4- 4c size or less that adds up to
no more than 12 STSs or 4 VC4s (that is, a total of 36 STSs or 12 VC4s on the card).
If STS-24c/VC4-8c circuits are not being dropped on the card, the full bandwidth can be used with no
restrictions (for example, using either a single STS-48c/VC4-16c or four STS-12c/VC4-4c circuits).
Because the STS-24c/VC4-8c restriction applies only when a single STS-24c/VC4-8c circuit is dropped ;
this restriction’s impact can be minimized. Group the STS-24c/VC4-8c circuits together on a card
separate from circuits of other sizes. The grouped circuits can be dropped on other G-Series cards.
Note The G-Series uses STS/VC cross-connects only. No VT level cross-connects are used.
Caution G-Series cards do not connect with ONS 15454 E-Series cards. For more information on interoperability,
see Chapter 20, “POS on ONS Ethernet Cards.”
G-Series Manual Cross-Connects
ONS nodes require end-to-end CTC visibility between nodes for n ormal provisioning of Ethernet
circuits. When other vendors’ equipment sits between ONS nodes, Simp le Network Management
Protocol/Target Identifier Address Resolution Protocol (OSI/TARP)-based equipment does not allow
tunneling of the ONS node TCP/IP-based data communications channel (DCC). To circumvent
inconsistent DCCs, the Ethernet circuit must be manually cross connected to an STS/VC cha nnel using
the non-ONS network. Manual cross-connects allow an Ethernet circu it to run from ONS node to ONS
node while utilizing the non-ONS network (Figure 23-5).
Note In this section, “cross-connect” and “circuit” have the following meanings: Cross-connect refers to the
connections that occur within a single ONS node to allow a circuit to enter and exit an ONS node. Circuit
refers to the series of connections from a traffic source (where traffic enters the ONS node network) to
the drop or destination (where traffic exits an ONS node network).
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Point-to-Point Circuit
ONS Node ONS Node
Gigabit Ethernet Gigabit Ethernet